Effects of oral administration of a mixture of amino acids on cardiac function in aged rats

Aging is associated with cardiovascular changes, and with impaired protein synthesis in muscles, including cardiac muscle secondary to increased risk of serious nutritional deficiencies coupled with reduced protein intake. The present study aimed at evaluating the effect of oral supplementation with a mixture of amino acids on cardiac inotropic and chronotropic properties of isolated hearts of aged rats and their responsiveness to beta- adrenergic stimulation. Rats were divided into 2 groups, a control group and amino acids [AAs] supplemented group. Isolated hearts were studied in a Langendorff apparatus for their intrinsic properties, and their responses to beta - adrenergic stimulation. At the end of the experiment, the isolated hearts were blotted dry, weighed and some hearts were subjected to histological study. The results showed that AAs-supplementation significantly increased the body weight, the absolute weights of right ventricle, left ventricle and whole heart as well as their relative weights to body weight. The baseline, maximum response to ISO infusion and the delta change of peak tension, the time taken to reach the peak tension and the maximum rate of tension development were significantly increased in hearts isolated from AAs supplemented rats compared to hearts isolated from the control rats. This was associated with non significant changes in heart rate, half relaxation time as well as myocardial flow rate. Histological studies revealed that AAs supplementation attenuates degenerative changes, decreases fibrosis and increases glycogen content of the hearts of the aged rats. Exogenous supplements of amino acids mixture could be a valid therapeutic strategy to improve mechanical performance of cardiac muscle in the elderly. Further research is recommended to explore the usefulness of AAs in cardiovascular disorders associated with systolic dysfunction

Effects of amikin administration on the spiral genglia of pregnant guinea PIGS: a light and electron microscopic study

Thirty healthy pregnant female guinea pigs [GPs] were assigned for this study. Fefteen GPs were injected with Amikin in a dose of 200 mg/kg. b.w., intraperitoneally for three weeks; from 40th to 60th days of gastation, where the maximum peiod of anatomical and functional maturation of the cocthlea takes place. The other fifteen pregnant GPs were assigned for the control group and were injected with slaine intraperioneally for the same period as the Amikin injected animals. After delivery, i.e. at birth, 15 newborns from each of the injected and control mothers were chosen for comparative morphological study of the spiral ganglia between the newborns and their mothers using light and electron microscopy. There types of spiral ganglion neurona cells. [SGNC], were recognized in the spiral ganglia of all studied animals viz; type I, type II and type III. Type I SGNC constiuted the majority of cell population in the control group; 95% in mother GPs and 90% in the newborn GPs type Ii percentage was 4% in the mother GPs and 9% in the newborn, GPs while, type III was 1% only in either two ages. Type I cells were surrounded by myelin sheath which was lacking around type II and type III, however it was noticed around the nerve fibers in both groups. The ganglion cells as well as the nerve fibers were capped by Schwann cells. Post natal maturation was evident in SGNC and nerve fibers espcially in the basal turn. Systemic administration of Amikin in pregnant GPs readily corssed the placental blood barrier and produced toxic effects on the spiral ganglia both in adults and their newborns. Neuronal degeneration was more obvious in the newborn GPs at birth than in the mothers also in the upper turns of the cochlea than in the basal turn. The cell density in the Amikin injected group was decreased than that of the control group. On the other hand, the mean cell diameter of the type I cells increased with apperance of vacoules in their cytoplasm and karryolysis of their nuclei. Separation and fasiculation of myelin lamellae, with clumping of myelin particles was observed in some cells, while other showed absence of their myelin sheath. Degenerative changes of the nerve fibers and Schwann cells were also noted. Type I cells were the most vulnerable cells, however, type II and III did not show any changes. The mode of action of Amikin ototoxicity is mainly, direct effect on ganlion cells as it occurred immediately, so early stimulation of deafferenated cells by cochlear implant may prevent secondary degeneration. Speech discrimination after cochlear implantation is expected to be better in local than in systemic aminoglycosides ototoxivity. Measurements of maximum diameter of the cochlear nerve by magnetic resonance imaging could be a pre dictor of remaining spiral ganglion cell cound and as a mean prognostication of success of implantation and speach perception

Intrahepatic bile duct development in the human foetus

This study included twenty human foetuses during various periods of gestation ranging from 9 to 40 weeks. The age of the foetus was approximately determined. Specimens from the liver were obtained and subjected to the appropriate histological and histochemical techniques. The data revealed that the bile duct system was immature at 9 weeks-old foetuses. Then at the 11th week, groups of hepatic cells were arranged in close contact with portal vein branches. At 12 weeks-old foetuses, the biliary ducts started to appear as small spaces among these groups of hepatic cells. At 18 to 20 weeks, portal spaces became obvious and duct-like structures were observed in the parenchyma-connective tissue contact area around these portal spaces. From the 21st week onwards, developing biliary structures were observed at the margins of the portal spaces. Then the portal mesenchymal tissue successively surrounded the bile ducts and pushed them inside portal spaces. At week 40, the number of large individual bile ducts increased in each portal area. The present results suggested that the cells lining the developing biliary structures originated from the hepatoblasts. The number of ductular structures per portal tract increased in full term foetal liver. Nevertheless, the bile canalicular system was less conspicuous till the full term gestational period suggesting that development will continue in the postantal life

Induced liver injury by oral intake of decline: an organic solvent

This study included 225 male albino rats; they were divided into three groups, each comprising 75 animals. The 1st group was used as control and given an oral daily dose of corn oil. The other groups were given decaline, which is an organic solvent widely used in industries. It was given orally in a daily dose of 0.5 g and 1 g/kg body weight for groups II and III, respectively. By the end of each week, 15 rats from each experimental group as well as 15 rats from control were sacrificed, this was executed for three weeks. Biochemical, histochemical, biological and ultrastructural studies were performed. The remaining animals of each group were sacrificed one week and two weeks after stoppage of the chemical intake. There were significant changes in level of serum enzymes between the different experimental groups, indicating a time and dose related phenomenon. Histological and ultrastructural examination of the liver cells proved that decaline produce hydropic degeneration, mainly in the periportal area of the hepatic lobule. By histochemical studies, it was found that glycogen content and SDH activity decreased in the degenerated cells, while alkaline phosphatase increased. All these changes appeared to be reversible by stoppage of the chemical intake