MINERAL, BONE AND JOINT

Drh. Herlina Pratiwi, M.Si

MINERAL

Mineral

Hewan perlu mineral dlm jumlah rendah untuk metabolisme

Elemen atom anorganik, merupakan nutrisi penting yang tidak berubah oleh digesti/metabolisme

Terdiri atas makro dan mikro mineral (trace elements)

Fungsi Mineral

Metabolisme Sistem saraf

Pembawa nutrisiKeseimbangan asam-basa tubuh

Kofaktor enzim

KLASIFIKASI MINERAL

• Calcium Phosphorus Magnesium Sodium Chloride Potassium Sulfur

MAKROMINERAL

• Chromium Cobalt Copper, Iodine Iron Manganese Molybdenum Selenium Zinc

MIKROMINERAL

Makro mineral

A number of inorganic

elements have been shown

to be essential for normal

growth and reproduction of

animals.

Those required in greater

quantities are referred to as

macrominerals and this

group includes calcium,

phosphorus, sodium,

chlorine, potassium,

magnesium, and sulfur.

The macrominerals are

important structural

components of bone and

other tissues and serve as

important constituents of

body fluids.

They play vital roles in the

maintenance of acid–base

balance, osmotic pressure,

membrane electrical

potential, and nervous

transmission.

Macrominerals are those

minerals required by the

body in large amounts each

day

In general their

concentration in a diet is

expressed on the basis of

percentage of the diet or in

grams per

kilogram diet.

Calcium (Ca)

KALSIUM EKSTRASELULER

KALSIUM INTRASELULER

Fungsi Ca:

•formation of skeletal tissues,

•transmission of nervous tissue impulses,

•excitation of skeletal and cardiac muscle contraction,

•blood clotting, and

•as a component of milk

EKSTRASELULER

•only 1/10,000th the concentration of extracellular calcium

• involved in the activity of a wide array of enzymes and

•serves as an important second messenger conveying information from the surface of the cell to the interior of the cell.

INTRASELULER

HOMEOSTASIS CA

❑ Calcitonin is a hormone producedby the thyroid gland in response to hypercalcemia.

❑ Calcitonin inhibits renal reabsorption of calcium from the glomerular filtrate, resulting in increased calcium excretion.

❑ It also inhibits bone calcium resorption, slowing entry of calcium into the extracellular fluid.

❑ Calcitonin is not often called on to restore calcium homeostasis unless a very high calcium diet such as milk is fed in a short period of time

Phosphorous (P)

■ 80% of P occurs in combination with Ca in the

bone and teeth.

■ About 10% is found in muscles and blood in

association with proteins, carbohydrate and lipids.

■ The remaining 10% is widely distributed in various

chemical compounds.

Phosphorous

Essential for the development of bones and teeth

Phospholipids, Phosphoproteins

Component of:DNA & RNA

ATP, NAD+, NADP+

Energy metabolism: ATP, GTP

Maintenance of blood pH: phosphate buffer system

Phosphorous

About 500 mg phosphate is excreted in urine per day. The reabsorption of phosphate by

renal tubules is inhibited by PTH.

Excretion:

Absorption:

Phosphate absorption occur from jejunum

1. Calcitriol promotes phosphate uptake along

with calcium.

2. absorption of P and Ca is optimum when the dietary Ca:P is 1:2-2:1.

3. acidity favors while phytate decreases

phosphate uptake by intestinal cells.

Phosphorous

Importance of Ca:P ratio

The ratio of plasma Ca:P is important for calcification of bones

Phosphorus Deficiency

Rickets, osteomalacia osteoporosis

Factors Regulating Ca and P

hormone

osteolysis

P excretion from kidney

osteogenesis

Ca excretion from kidney

Blood phosphorus

Blood calcium

1,25 DHCC

Ca absorption in intestine

PTH CT

↑↑ ↑ ↓

↑

↓

↑

↑

↑

↑

↑

↑ ↑↑ ↓

↓ ↓

↓ ↑

↑

↑

↓

↓

Sodium (Na)

■ Fungsi :

– Keseimbangan osmosis cairan tubuh

– Keseimbangan pH

– Kation utama CES

– Transmisi saraf

– Transpor dan absorbsi glukosa dan

asam amino

❖ Absorbsi pada kolon

❖ Regulasi oleh aldosteron

SODIUM (2)

Potassium (K)

Kebutuhan meningkat pada heat stress

Pada keringat mamalia kandungan tinggi

Fungsi :

Keseimbangan osmosis cairan

tubuh

Keseimbangan pH

Kation utama CIS

Kofaktor metabolisme karbohidrat

Potassium

Deficiency

Diarrhea & vomiting

Diuretik

Hypokalemia

Symptoms

Kelemahan otot, konstipasi, iritabilitas, konvulsi, irregular heart, tekanan darah ↓, sulit bernafas

Magnesium (Mg)

MAGNESIUM EKSTRASELULER

MAGNESIUM INTRASELULER

Magnesium intraseluler

Magnesium is a major intracellular cation

that is a necessary cofactor for enzymatic

reactions vital to every major metabolic

pathway.

The intracellular magnesium concentration is

about 13 mmol/L, making it the second most

abundant cation found inside

of cells.

Magnesium Ekstraseluler

Magnesium is vital to normal

nerve conduction

Plasma magnesium

concentration is normally 0.75–

1.0 mmol/L or 1.8–2.4 mg/dL

Normal bone formation also

requires magnesium

Homeostasis Mg

Despite the importance of magnesium, there is no hormonal

mechanism concerned principally and directly with magnesium

homeostasis.

The kidneys play a key role in maintaining magnesium

homeostasis, but only under conditions of hypermagnesemia.

Magnesium is absorbed primarily from the ileum and colon of

monogastric animals and young ruminants.

Magnesium absorption is by passive absorption and is therefore

dependent on the concentration of magnesium ions in the

digesta.

As the rumen and reticulum develop, these organs become the

main, and perhaps only, site for magnesium absorption in adult

ruminants.

In adult ruminants the small intestine is a site of net secretion of

magnesium.

Deficiency – Hypomagnesemic tetany (grass

tetany)

■ Awal laktasi

■ Kontrol syaraf & otot buruk

Chloride (Cl)

Chloride is the chief anion of the extracellular fluid and plays a role in maintaining osmotic pressure and water content (extracellular volume) of the circulation

As one of the strong ions of the blood, it plays a key role in acid–base balance of the body.

Chloride also plays a small role in determining the electrical potential of nervous tissue

Chloride is pumped into the lumen of the stomach to form hydrochloric acid (HCl), which aids in digestion.

Chloride also plays a vital role in oxygen and carbon dioxide transport by red blood cells, the so‐called “chloride shift.”

Extracellular chloride concentration is 100–113 mmol/L, depending on the species of animal and their blood acid–base status.

Intracellular chloride concentration is about one‐tenth that of the extracellular fluid.

SULFUR (S)

About 0.15% of body weight is

sulfur

Sulfur is found in the amino

acids methionine, cysteine

(cystine), homocysteine, and

taurine

Sulfur is also found in

chondroitin sulfate of

cartilage, and in the B

vitamins thiamine and biotin

The disulfide bonds of the

sulfur‐containing amino acids

are largely responsible for

determining the tertiary

structure of proteins.

Oxidation of methionine and

cysteine causes sulfur to also

exist in tissues as the sulfate

anion, which influences the

acid–base status of the

animal.

Methionine, thiamine, and biotin cannot be synthesized by mammalian tissues and these nutrients must be supplied in the diet.

When provided with adequate substrates (nitrogen, energy and sulfur), rumen microbial synthesis of methionine, thiamine, and biotin can supply enough of these compounds to the ruminant to meet daily requirements, with the possible exception of very high producing cows.

Therefore only ruminants can be said to have a dietary requirement for sulfur.

MetabolismeS

Sulfur incorporated into microbial protein is absorbed within the small intestine as cysteine and methionine.

Some dietary sulfur is absorbed as the sulfate or sulfide anion.

Sulfide is absorbed more rapidly and efficiently from the rumen of sheep than is sulfate.

Sulfate sulfur is absorbed more efficiently in the small intestine.

Trace minerals

■ Those elements required in much smaller amounts are

referred to as the trace minerals.

■ This group includes cobalt, copper, iodine, iron,

manganese, molybdenum, selenium, zinc, and perhaps

chromium and fluorine

■ The trace minerals are present in body tissues in very

low concentrations and often serve as components of

metalloenzymes and enzyme cofactors, or as

components of hormones of the endocrine system.

Trace elements

Selenium Melindungi sel dari autooxidative apoptosis, antioksidan, mengikat vitamin E

ZincSintesis RNA, antioksidan, menstabilkanmembran sel

IodineHormon thyroid, regulasi temperatur, basal metabolic rate, reproduksi, pertumbuhan

IronEritrosit, transpor elektron, imunitas, gluconeogenesis

BONE

HistologiTulang

Osteoblast

Osteosit

Osteoklast

Lining cells

Lakuna

Kanalikuli

Kanalis sentralis

Lamella

HISTOLOGI TULANG

HISTOLOGI TULANG

FungsiTulang

Penunjang

Perlindungan organ

Pergerakan tubuh perlekatan otot

Penyimpanan Ca2+ dan PO4

Bone Development

Bone is consist of organic and anorganic matrix

Organic matrix 30%

Anorganic 70%

■ Organic matrix

– Serabut kolagen dengan glisin, prolin,

dan hidroksipolin yang tinggi

– Kolagen untuk?

– Diperkuat oleh deposisi Ca

– Ikatan struktur difasilitasi oleh

osteoblas dengan menghasilkan :

■ Osteocalcin (mengikat Ca)

■ Osteonectin (ikatan Ca-kolagen)

– Substansi dasar ini berfungsi untuk ?

■ Pertukaran nutrisi, O2, dan sisa

metabolisme

Bone development

■ Inorganic matrix

– Dominasi Ca dan P dalam bentuk

kristal hidroksiapetite

– Kristal terletak di permukaan dan

sekitar kolagen

– Fungsi kristal ?

– Pertukaran ion di permukaan kristal

untuk buffer system

– Terdapat magnesium, potassium,

sodium : but not crystallized

Bone development

Bone development

How about bone development ?

Osteoblast sekresi monomer kolagen dan proteoglikan -> dalam beberapa hari kalsiummulai mempresipitasi permukaan -> dalam

waktu minggu atau bulan -> kristalhidroksiapetit

Osteoblast terperangkap dalam ruang kosong -> osteosit

Bone resorption

Bone and Calcium Physiology

•Osteoklast mengeluarkan enzim proteolitik dan berbagai jenis asam (asam laktat, asam sitrat) untuk degradasi ikatan garam anorganik

•Osteoklast berikatan dengan kristal melalui ikatan integrins-vitronectin

•Degradasi kristal membuat Ca dan P tulang kembali bebas dan menuju plasma

How about bone resorption ?

Bone resorption

■ Faktor faktor yang mempengaruhi Bone resorption (BR) :

– Parathyroid hormon (PTH)

■ Penempelan PTH di reseptor osteoblast membuat release-nya IL-6 dan RANK dari

osteoblast untuk inisiasi BR

■ RANK menuju reseptornya di osteoklast lalu mengaktivasi BR

– Vitamin D dan PTH

■ Bersama menstimulasi osteoblast menghasilkan M-CSF untuk proliferasi osteoklast

Bone resorption

– Osteoblast memiliki regulasi untuk mencegah terjadinya BR, yaitu dengan cara

mensekresikan osteoprotegerin yang memblok RANK sehingga RANK tidak

dapat menempel di reseptornya di osteoklast, sehingga osteoklast tidak

memulai BR

– Bone and Calcium Physiology Video

Metabolisme Ca dan Tulang

■ Homeostasis Ca plasma

■ Fungsi Ca ??

■ 99% di tulang dan gigi, 0,9% intrasel,

0,1% CES

MetabolismeCa dan Tulang

Parathyroid hormon (PTH)

Calcitonin

Vitamin D

Renal system

Intestine absorbtion

Parathyroid Hormon

(PTH)

Diproduksi oleh sel chief dari glandula parathyroid

•Memindahkan Ca dari labile pool cairan tulang ke plasma -> cepat

•Memindahkan Ca dari stabile pool (matriks tulang kompak) ke plasma -> lambat

•Reabsorbsi Ca oleh ginjal dengan mendorong ekskresi P

•Meningkatkan pengaktifan vitamin D oleh ginjal

•Meningkatkan absorbsi kalsium di saluran pencernaan

Meningkatkan Ca plasma dengan cara :

Calcitonin

Diproduksi oleh sel parafolikuler dari glandula thyroid

Berkebalikan kinerja dengan PTH

• 1. bone: stimulate osteoclasts become osteoblasts, osteogenesis

• 2. intestine: inhibit absorption of Ca

• 3. kidney: enhance of Ca excretion from urine

Menurunkan Ca plasma dengan cara :

Vitamin D

Disebut juga kolekalsiferol

Dapat disebut hormon karena dapat diproduksi

di kulit

Perlu diaktifkan di hepar

dan ren menjadi :1,25-(OH)2-Vit D3 atau

1,25DHCC

Bekerjasama dengan PTH untuk meningkatkan

Ca plasma dengan cara meningkatkan

absorbsi Ca pada saluran pencernaan

FRAKTUR

Gangguanmetabolisme

Ca

•Gangguan saraf : Kelemahan otot, depresi, letargi, koma

•Gangguan pencernaan : konstipasi, anoreksia, muntah, ulcer peptic

•nephrocalcinosis

Hipercalcemia :

•Osteoporosis / osteomalacia

•Gangguan saraf

•Milk fever

Hipocalcemia :

JOINT

Joint

The junction between any two bones is known as an articulation

Their function is to provide a means of attaching one bone to another in such a way that the bones can withstand high impact forces yet still allow the bones to “swing” freely with little resistance

The movement of a joint is controlled and limited by the action of muscles and passive structures such as ligaments and tendons.

SINOVIAL

■ Synovial joints contain a capsule that has an outer fibrous layer

consisting of collagen fibers that run from the periosteum of one bone

to the periosteum of the other bone, lending side‐to‐side stability to the

joint.

■ Ligaments are specialextensions of the fibrous capsule that can be

located on the inside or outside of the joint capsule. The inner surface

of the joint capsule is composed of the synovial membranes.

■ The synovial membranes are involved in the production of synovial fluid,

a very viscous liquid with a consistency similar to egg white. It is

essentially an ultrafiltrate of blood plasma to which the synovial cells

have added substances such as hyaluronic acid and proteins such as

lubricin. Synovial fluid provides lubrication to the joint, reducing wear on

opposing articular cartilage surfaces.

MENISKUS

Menisci are special areas of dense fibrocartilage that exist between the articulating cartilage surfaces of some bones, especially those that are bearing great weight.

The menisci function to cushion compressive forces acting on the ends of bones.

Articular cartilage covering the ends of the bones involved in the joint provides further cushioning over that which might be achieved by two ossified surfaces coming in contact with each other.

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