IMPAIRED SPERM CHARACTERISTICS IN POSTPUBERTAL GROWTH-HORMONE-DEFICIENT DWARF (DW DW) RATS/

The objective of the current study was to determine if sperm function is compromised in rats deficient in growth hormone (dw/dw) since a def iciency in this hormone has been implicated as a cause of lowered fert ility and spermatogenic cessation in some biological models. Spermatoz oa were recovered from the cauda epididymides of adult dwarf and Wista r control male rats. Spermatozoa were diluted in Medium 199 and analys ed for motility. Aliquots were then fixed in phosphate buffered formal in, sperm concentration determined and morphology assessed. The mean m easurements for percent motile and normal morphology were compared by Student's t-test. Sperm concentrations were compared by Mann-Whitney t wo sample test. The mean percentage of motile spermatozoa was signific antly greater in the Wistar control group than in the dwarf group (75 +/- 1.44 vs 28 +/- 3.71%, P < 0.001). The percentage of normal sperm m orphology was also greater in the Wistar control group (88 +/- 1.00 vs 75 +/- 6.9%, P < 0.001). The concentration of spermatozoa in the caud a epididymis was also significantly higher in the Wistar group. These results indicate that sperm function parameters are diminished in grow th-hormone-deficient dw/dw rats. The effects of growth hormone deficie ncy in rats appears to be associated with compromised spermatogenesis as well as impaired sperm motility. The GH-deficient rat appears to be a suitable model for the study of the effects of GH on sperm characte ristics. (C) 1997 Elsevier Science B.V.