Effects of the method of exsanguination on measurements of developmental changes in serum concentrations of follicle-stimulating hormone and luteinizing hormone in prepubertal and adult male house mice.

The relationship between the method of exsanguination and the serum concentration of gonadotrophins was investigated in male house mice. Mice were killed 21-99 days post partum by ether anaesthesia and cardiac puncture, or by decapitation. Results of gonadotrophin radioimmunoassays indicated that titres of serum FSH were not affected by the method of exsanguination, while concentrations of serum LH were significantly raised when blood was collected by ether anaesthesia and cardiac puncture. Serum FSH in an inbred strain of mice peaked at 21 days post partum and declined steadily to a relatively constant pubertal and postpubertal level. Concentrations of serum LH were variable during the prepubertal period with a peak occurring 31--35 days post partum. Extremely high titres of FSH on days 21-35 post partum indicated that mice in this study might be relatively insensitive to FSH in the prepubertal period.