Spermatozoal morphologies and fructose and citric acid concentrations in agouti (Dasyprocta leporina) semen.

This study was conducted to identify the levels of fructose and citric acid, and sperm morphologies in agouti (Dasyprocta leporina) semen. These parameters may be important in identifying highly fertile semen from the agouti. The objectives were: (1) to investigate spermatozoal abnormalities in agouti semen and (2) to determine the concentrations of seminal fructose and citric acid in agouti semen samples. Semen samples were collected from 16 anaesthetised male agouti by electro-ejaculation. Fructose and citric acid concentrations were 256.86+/-63.54 mg/dl and 1877+/-147 mg/dl, respectively, measured with ELISA kits. Sperm morphologies, examined using eosin-negrosin staining, showed 11 morphologies. The most abundant (68.5 per cent) sperm morphology (M1) showed no known sperm defects. Means for head, mid piece, tail and total length of the agouti spermatozoa was 5.23+/-0.04 microm, 5.18+/-0.08 microm, 37.52+/-0.24 microm and 47.96+/-0.25 microm, respectively for M1 sperm. The means of spermatozoa head and mid piece width and semen volume were 3.26+/-0.04 microm, 0.70+/-0.02 microm and 0.47+/-0.16 ml, respectively. It was concluded that as the fructose concentration in agouti ejaculate increased the percentage of spermatozoa with known spermatozoa defects increased (r=0.506; P<0.037; n=32). It is suggested that the M1 sperm could be the most competitive spermatozoa in agouti ejaculate. In conclusion standards for identifying fertile agouti semen were established.

The effect of phenyl ethyl biguanide in vivo and in vitro on gluconeogenesis and ammonia production in rats

The drug phenyl ethyl biguanide (PEBG) was used in vivo and in vitro to study further the relationship between renal gluconeogenesis and ammonia production in the rat. When PEBG was injected intraperitoneally into the rats, it caused a decrease in urinary ammonia in spite of a greater degree of systemic acidosis. PEBG injections also blocked the increase in glucose and ammonia production by renal cortical slices from rats which had been made acidotic by oral administration of ammonium chloride 2h previously. With increasing concentrations of PEBG in vitro, there was inhibition of gluconeogenesis and ammonia production from glutamine and glutamate as substrates. The two processes were equally inhibited when glutamate was used as substrate but with glutamine, gluconeogenesis was more inhiblted than ammonia production. The inhibition of renal gluconeogenesis by PEBG in vitro was similar when succinate, oxaloacetate, fructose, glutamine and glutamate were used as substrates. The results show that PEBG does not inhibit gluconeogenesis by blocking a specific site in the gluconeogenic pathway. In addition, further proof is provided of the physiological interrelationship of renal ammonia production and gluconeogenesis (Summary)