Date of Award

1-1-1986

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Anatomy and Cell Biology

Abstract

Hypogonadism in the male is a well known clinical symptom of zinc deficiency. The testicular lesions have been primarily attributed to the effects of decreased zinc on germ cells. This study assessed possible effects of zinc deficiency on Sertoli cell number and ultrastructure.Long-Evans dams and their newborn litters were placed on zinc deficient (ZD), pair-fed or ad libitum fed (AL) diets. All dams received a 20% egg white based diet containing less than one ppm zinc. ZD dams received distilled, deionized water (<1 ppm ZN), while PF and AL dams received the above water fortified with 25 ppm zinc. Male pups were sacrificed day 10 and their testes were processed for light (LM) and transmission electron microscopy (TEM).LM cell counts were performed on one (mu)m sections. Average number of germ cells on the basement membrane (BM) (=GC2) per tubular cross-section was reducted by two-thirds in ZD and PF compared to AL animals (p < 0.0001). Average number of germ cells not on the BM (=GC1) and average number of Sertoli cells per tubular cross-section were not statistically different in the three diet groups.Volume fractions of TEM subcompartments/total cytoplasm were determined by morphometric methods. The lysosome-like fraction was doubled in ZD and PF compared to AL animals (p < 0.05). Endoplasmic reticulum, Golgi and mitochondrial fractions were not statistically different in the three diet groups.Five day old Sertoli cell cultures derived from ZD, PF and AL pups were volumetrically analyzed as in vivo. The endoplasmic reticulum fraction was approximately 100% lower in ZD- than in AL-derived cultures (p < 0.01). Golgi, mitochondrial, dense body and inclusion body fractions were similar in ZD-, PF- and AL-derived cultures.These data suggest that Sertoli cells, although not significantly reduced in number in ZD and PF animals, were affected ultrastructurally by dietary treatment. The volumetric increase in lysosome-like bodies in vivo suggested that Sertoli cells participate in phagocytosis of germ cells degenerating as a result of dietary treatment. The decreased ER volume fraction of ZD-derived tissue cultured Sertoli cells suggested that Sertoli cell secretory potential may be altered as a result of zinc deficiency.

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