Abnormal human spermatozoa including comparative data from apes

Abstract

Several reports have shown that the sperm counts in man have declined over the last 20 years. Human spermatozoa also exhibit a structural and chemical variation that is greater than that of most other mammals. Human fecundability is low compared with other examined animal species. Possible causes of these three classes of findings are analyzed: The effect of clothing or of other undue heating of the scrotum; xenobiotic influences such as smoking, lead compounds, X-rays, alkylating agents; degeneration effects, and mating habits. Comparative data from the great apes are of interest, as spermatozoa from the gorilla but not from the chimpanzees and orangutan show a structural variation similar to that of human spermatozoa. A classification of the different types of abnormal spermatozoa is given and the possible causes-genetic or environmental-for each subgroup of abnormal sperm pattern are presented.

Hyperthermia and human spermatogenesis: enhancement of the inhibitory effect obtained by ‘artificial cryptorchidism’

“…5). The mean per cent of sperm with abnormal forms remained slightly above baseline values at 18 months post-treatment, although the actual values (28-35%) are within the normal range for men (Afzelius, 1981;Schwartz et al, 1984).…”

“…Such a decrease in motility could result from alteration of sperm motility during transit through the cauda epididymis, which is known to be thermo-dependent in animals (Foldesy & Bedford, 1982). Another cause could be a structural abnormality of the sperm tail, linked to impairment of sperm differentiation within the seminiferous tubules, as evidenced by the increased rate of abnormally shaped sperm (Afzelius, 1981). Scanning electron microscopy could help to resolve this question.…”

Semen parameters and electron microscope observations of spermatozoa of the red wolf, Canis rufus

“…There are a few examples of species that have large numbers of morphologically abnormal spermatozoa and propagate effectively, including cheetahs (Wildt et al, 1983) and primates such as humans and gorillas (Afzelius, 1981). However, the great majority of animal species studied Fig.…”

Study of Sperm Morphologic Characteristics in a Group of 833 Fertile Men

“…The high rate of morphological abnormalities differentiates human sperm from that of other species (MacLeod -1964). It has been suggested that this difference might be related to environmental factors and/or to people's habits (Afzelius -1981). It has been possible, for example, to induce morphologic abnormalities in the mouse by using different chemical agents (Wyrobek and Bruce -1975).…”