A crosstalk between 'osteocyte lacunal-canalicular system' and metabolism.

Considering the importance, bone physiology has long been studied to understand what systematic and cellular impact its cells and functions have. Exploring more questions is a substantially solid way to improve the understanding of bone physiological functions in/out sides. In adult bone, osteocytes (Ots) form about 95% of bone cells and live the longest lifespan inside their mineralized surroundings. Ots are the endocrine cells and originate from blood vessel's endothelial cells. In this work, we discussed the vital role of the "Ots". To determine the association between osteocytes' network with metabolic parameters in healthy mice, the experiments were performed on ten (10) adult C57BL6 male mice. Fasting blood and bone samples were collected weekly from mice for measurement of metabolic parameters and bone morphology. Scanning electron microscopy (SEM) revealed a 2D fine morphology of the bone which indicates a strong functional interconnection with bone nano/micro, and macro components of the organs. The long-branched canaliculi look like neurocytes in structure. The morphology and quantitative measurements of the osteocyte lacunal-canalicular system showed its wide spectrum spatial resolution of the positive and negative relationship within this system or metabolite parameters, confirming a strong cross connection between osteocyte lacunal-canalicular system and metabolism. We believe that the findings of this study can deliver a strategy about the potential roles of metabolic relation among osteocytes, insulin, and lipid in management of bone and metabolic diseases.

Evidence for the presence of oxytocin in the corpus luteum of the goat.

Purified acetic acid extracts of corpora lutea (CL) of non-pregnant goats were found to contain substantial amounts of oxytocin (OT) as measured by radioimmunoassay. OT standard and the CL extracts released prostaglandin F2 alpha (PGF2 alpha) from rat isolated uteri in a quantitatively similar manner. Treatment of both OT standard and CL extract with sodium thioglycolate, oxytocin antiserum or oxytocin antagonist abolished this biological activity. Acid extracts of CL of pregnant goat were found to contain approximately 2% of levels during the cycle by day 21 after fertile mating and this had a reduced ability to release PGF2 alpha from rat uterus. It is concluded that both the immunoreactivity and the biological activity of the CL extracts are due to the presence of an oxytocin-like substance and that tissue levels of oxytocin are low in pregnant compared to non-pregnant goats.

Effects of oxytocin-antagonist injections on luteal regression in the goat.

Intra-arterial administration of 0.25 ml physiological saline to the non-pregnant goat between days 12 and 20 of the oestrous cycle did not affect luteal regression, which was characterized by decreasing peripheral plasma progesterone concentration, beginning on day 13 of the oestrous cycle, and an increase in the plasma concentration of 13, 14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) as oestrus approached on about day 20. Intra-arterial administration of oxytocin antagonist (OA) in saline at a dose of 0.2 microgram kg-1 body weight to goats between days 12 and 20 of the cycle significantly (P less than 0.001) delayed luteal regression beyond day 20 (to day 26). Injection of OA maintained plasma progesterone secretion at 4-5 ng ml-1 till day 23 of the cycle and suppressed the increase in PGFM concentration. Corpus luteum extract (100 microliters) of OA-treated animals released a significant (P less than 0.001) amount of PGF2 alpha from rat uterus in vitro as did authentic oxytocin. This oxytocic material failed to release PGF2 alpha during luteolysis in the goat, suggesting that oxytocin receptors for PGF2 alpha release may be occupied by OA. It is concluded that oxytocin-receptor interaction in the uterus may be the stimulus for PGF2 alpha release which triggers luteal regression in the goat.

Secretion of neurophysins during luteal regression in the goat.

In non-pregnant goats, ovariectomy on day 12 of oestrous cycle resulted in parallel decrease of oxytocin and progesterone jugular concentration. Similarly, luteolysis, indicated by decreasing progesterone concentration, was accompanied by simultaneous release of oxytocin and oxytocin-associated neurophysins (mean of neurophysin I and II). It is suggested that the neurophysins are secreted concomitantly with oxytocin by the ovary during luteal regressions in the goat.

Effect of antibacterial growth promoters on the immune system of broiler chicks.

Administration of either 0.001 g/kg ampicillin (A), 0.05 g/kg oxytetracycline (O) or 0.05 g/kg sulphadimidine (S) in feed to broiler chicks for 50 days caused an increased serum concentration of the drug compared to the control birds that were given no drugs. O and S but not A resulted in a significant decrease of the total number of leukocytes, lymphocytes and the size of bursa of Fabricius and thymus but not spleen or body weight. The antibacterials significantly reduced the macrophage phagocytic activity compared to controls. It is suggested that the prolonged administration of O and S to chickens may induce an immunosuppressant effect.

Investigation of the antispasmodic potential of Hibiscus sabdariffa calyces.

Addition of an aqueous extract of Hibiscus sabdariffa calyces (2.5 ml/bath approximately 125 mg of starting crude material) inhibited the tone of various isolated muscle preparations (rabbit aortic strip, rhythmically contracting rat uterus, guinea-pig tracheal chain and rat diaphragm). Other muscles were stimulated (quiescent rat uterus and frog rectus abdominis). Intravenous injection of the extract to anaesthetized cats lowered the blood pressure in a dose-response manner. The inhibitory effects were resistant to a number of standard receptor blockers but the hypotensive influence was partially blocked by atropine and the tonic effects on rat uterus were partially reduced by hydrocortisone and indomethacin.

Prevention of the luteolytic action of oxytocin in the goat by inhibition of prostaglandin synthesis.

Oxytocin-induced luteolysis in goats was associated with significant increases in peripheral plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F2alpha (PGFM). Oral administration of the prostaglandin (PG) synthetase inhibitor meclofenamic acid (l g/day) prevented both the luteolytic action of oxytocin and the increase in PGFM concentrations. These results confirm that the luteolytic effect of oxytocin is mediated via the production and release of PGF2alpha.

Plasma concentrations of 13, 14-dihydro-15-keto prostaglandin F(2alpha) and progesterone during oxytocin-induced oestrus in the goat.

Fertile oestrus was induced in dairy goats by sub-cutaneous administration of 100 i.u. oxytocin per day between days 3-6 of the oestrous cycle. Peripheral plasma concentrations of 13, 14-dihydro-15-keto-prostaglandin F(2alpha) (PGFM), the major metabolite of prostaglandin (PG) F(2alpha), were elevated significantly (P<0.001), relative to controls, 30 minutes after oxytocin with peak values of between 300-800 pg ml(-1). Unlike control animals, plasma progesterone concentrations did not rise in the oxytocin-treated group after day 4. These results lend support to the hypothesis that the luteolytic effect of oxytocin in goats may be mediated via uterine PG production.

Oxytocin-induced biochemical changes in cervical mucus of the goat.

This study was conducted to investigate the effects of oxytocin administration on plasma progesterone concentration and cervical mucus content of protein and acid and alkaline phosphatase activity in the goat. Oxytocin administered to goats (100 IU, S.C. daily) between Days 3 and 6 of estrous cycle induced estrus and resulted in a corresponding decrease in the levels of plasma progesterone, as well as in the contents of protein and in acid and alkaline phosphatase in the cervical mucus. Administration of indomethacin (10 mg/kg body weight, S.C.) inhibited oxytocin-induced estrus and changes in progesterone, protein and enzymes. It is suggested that oxytocin-induced changes are mediated via the production and release of prostaglandin F2alpha (PGF2alpha).

The activities of drug-metabolizing enzymes in goats treated orally with the latex of Calotropis procera and the influence of dieldrin pretreatment.

The effects of oral administration of different doses of the latex of Calotropis procera on the activities of drug-metabolizing enzymes in the liver, kidneys and duodenal mucosa of Nubian goats were investigated. Lesions and changes in total plasma protein concentration and in the activities of plasma sorbitol dehydrogenase (SD), glutamate dehydrogenase (GD) and aspartate aminotransferase (AST) were studied. The daily oral administration of the latex at dose rates of 0.4 and 0.8 ml per kg for 7 days resulted in a significant inhibition of the activity of aniline 4-hydroxylase. No signfiicant effects on the activities of aminopyrine N-demethylase and UDP-glucuronyltransferase were observed. A single oral dose of 1.2 or 1.6 ml per kg killed goats within 7 h and resulted in increased activities of aminopyrine N-demethylase and aniline 4-hydroxylase. UDP-glucuronyltransferase was found to be insensitive to tissue injury induced by the latex of C. procera. There were no pathological changes in goats given 10 mg per kg of dieldrin alone or in those pretreated with dieldrin and given the latex at a dose rate of 1.2 ml per kg 14 days later. Dieldrin pretreatment resulted in the induction of the activities of drug-metabolizing enzymes in the liver, kidneys and duodenal mucosa and it may have protected goats from the lethal effects of the latex.

Effect of PGF2 alpha administration on the release of endogenous PGF2 alpha and oxytocin in indomethacin-treated goats.

Repeated intramuscular injection of 1 mg prostaglandin F2 alpha (PGF2 alpha) during the luteal phase of the oestrous cycle of the goat hastened luteolysis and resulted in rapid increases in jugular concentrations of 13,14-dihydro-15-keto PGF2 alpha (PGFM), the primary metabolite of PGF2 alpha, and of oxytocin; similar injections of PGF2 alpha in indomethacin-treated goats had a reduced effect on PGFM and oxytocin concentrations, and failed to induce luteolysis. The same injections of PGF2 alpha were without effect on PGFM and oxytocin concentrations in ovariectomised goats. The results suggest that exogenous PGF2 alpha, or endogenous PGF2 alpha released at luteolysis, may induce the release of ovarian oxytocin in the goat.

Delayed luteolysis and suppression of the pulsatile release of oxytocin after indomethacin treatment in the goat.

Luteolysis in the goat was characterised by the pulsatile appearance of both oxytocin and 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM), the primary pulmonary metabolite of prostaglandin (PG) F2 alpha, in the peripheral circulation. The episodic, surge release of oxytocin was superimposed on declining levels which paralleled the fall in progesterone concentrations. Daily subcutaneous administration of the prostaglandin synthetase inhibitor indomethacin (10 mg kg-1) between days 11 and 16, delayed luteolysis and suppressed both the decline in oxytocin concentrations and the pulsatile appearance of both oxytocin and PGFM in the peripheral circulation. Although there was little evidence of the release of the two hormones being synchronised, the results suggest that PGF2 alpha may stimulate pulsatile oxytocin release at luteolysis.

Biological half-life of oxytocin in the goat.

The disappearance of oxytocin from the peripheral circulation of the goat after a single intravenous injection followed a biexponential curve. The mean (+/- SD) half-life, calculated from the slower component of this decline, was 22.3 +/- 0.6 minutes. The volume of the central compartment was about twice the volume of the vascular compartment and the total apparent volume of distribution was more than twice the size of the extracellular compartment.

Loss of biological and immunological activity of oxytocin from goat plasma on storage.

Storage of plasma at -30 degrees C, with no prior treatment, resulted in significant (P less than 0.01) reductions in the biological and immunological activities of oxytocin after 10 days and further reductions after 20 days. Acidification with 0.1 N hydrochloric acid, or snap-freezing in solid carbon dioxide-acetone, before storage afforded some protection against these losses and a combination of both treatments preserved the biological and immunological activities for 20 days despite thawing and refreezing after 10 days.

Pharmacokinetics of progesterone in dromedary camels (Camelus dromedarim).

The effect of ovariectomy or administration of progesterone (P4) on the disposition kinetics of P4 was determined in dromedary camels. The disappearance of P4 from peripheral circulation of the camel following ovariectomy or after a single intravenous (I.V.) injection of 1 mg kg(-1) body weight followed a bioexponential curve. Both curves were parallel indicating that the disappearance of injected P4 behaved similarly to endogenous P4. The mean (+/- SD) half-life calculated from the slower component of this decline, was 26.0 +/- 2.0 min after I.V. injection of P4 and 28.0 +/- 2.1 min after ovariectomy. The apparent volume of distribution (1370 ml kg(-1)) exceeded total body water suggesting extensive tissue penetration.

Uterine activity after ovariectomy in the camel (Camelus dromedarius): effect of exogenous administration of oestrogen and progesterone.

During oestrous cycles of the camel, spontaneous uterine contractions were correlated significantly with plasma oestradiol-17 beta concentration. Ovariectomy in the camel resulted in a decreased plasma concentration of oestradiol-17 beta (< 15 pg ml-1) and progesterone (< 0.1 ng ml-1) and caused complete cessation of uterine activity. Daily administration of oestradiol benzoate (5 mg, intramuscularly) increased the plasma concentration of oestradiol-17 beta (> 45 pg ml-1) and increased the frequency and amplitude of uterine activity. Coadministration of progesterone (100 mg, intramuscularly) increased the plasma concentration of progesterone (> 4 ng ml-1) and increased the frequency but not amplitude of uterine activity. It is suggested that uterine activity in the camel is correlated with the circulating levels of oestradiol-17 beta and progesterone.

Uterine activity after induction of hypocalcaemia in the ovariectomized camel (Camelus dromedarius).

Bilateral ovariectomy was performed in three parous, non-pregnant camels. Intrauterine and intraabdominal pressure changes were recorded using balloon-tipped catheters. Uterine contractions were induced and maintained in the ovariectomized camels by daily intramuscular injections of 5 mg oestradiol benzoate throughout the experimental period. The frequency of uterine contractions varied from 6 to 9 per minute, whereas the amplitude varied from 2 to 3 kPa in all the animals. Inducing hypocalcaemia to a level of 0.5 mmol/L by Na2EDTA reduced the amplitude of the contractions to below 1 kPa (p < 0.001). The frequency of the contractions was not affected.

Effect of endotoxin administration in pregnant camels.

Intravenous administration of Escherichia coli endotoxin at a dose of 0.05 µg/kg bodyweight to pregnant camels resulted in abortion. The injection of endotoxin caused significant increases in the plasma concentration of 13,14-dihydro-15-prostaglandin F2α, the metabolite of prostaglandin F2α (PG F2α) and cortisol and a significant decrease in the concentration of progesterone. It is suggested that endotoxin caused abortion in camels was a consequence of endotoxin induced PG F2α secretion resulting in luteal regression and decreased progesterone concentration.

Coagulation profile and platelet parameters of the Arabian sand gazelle (Gazella subgutturosa marica): comparison with humans and camels.

During March 2009, we evaluated the hemostatic profile and platelet indices of 18 Arabian sand gazelles (Gazella subgutturosa marica) and compared the results with those from humans and camels (Camelus dromedarius). Gazelles and camels had shorter activated partial thromboplastin times, lower proconvertin and higher antihemophilic factor coagulation activity, and plasma fibrinogen levels than humans. Prothrombin time was longer in sand gazelles and shorter in camels than it was in humans. Plasma thromboplastin component, Stuart factor, and plasma thromboplastin antecedent were similar in gazelles, humans, and camels, whereas the platelet count of the sand gazelle was significantly higher than it was for camels and humans.