Injection of a chemical castration agent, zinc gluconate, into the testes of cats results in the impairment of spermatogenesis: a potentially irreversible contraceptive approach for this species?
Male sterilization by chemical agents is a nonsurgical contraceptive approach designed to induce azoospermia and, therefore, infertility. Intratesticular injection of zinc gluconate for sterilization of dogs has been described, but its use in cats remains limited. The objective of the present study was to evaluate, by light and transmission electron microscopy, the efficacy of a single intratesticular injection of a zinc gluconate solution (Testoblock) as a sterilant for male cats. Twelve sexually mature mixed breed cats were allocated at random into two groups (control = 6; treated = 6) and given a single injection into each testis of either isotonic saline or zinc gluconate, respectively. Histopathologic and ultrastructural evaluation was assessed at 120 days postinjection. Histopathologic changes were not detected in the testes from the control group. However, histologic evaluation of the treated group revealed atrophic and dilated seminiferous tubules, a decrease in the number of germ cells, and incomplete spermatogenesis. Sertoli cells had various degrees of cytoplasmic vacuolization. Intertubular tissue revealed active fibroblasts, collagen deposition, and inflammatory cells. The diameter of seminiferous tubules, epithelial height and tubular area were reduced (P < 0.05) in the treated group compared with controls. Azoospermia occurred in 8 of the 11 treated cats (73%). Ultrastructural evaluation of Leydig cells revealed loss of nuclear chromatin, increased smooth endoplasmatic reticulum, and mitochondria degeneration. Intratesticular injection of zinc gluconate solution impaired spermatogenesis in cats and has great potential as a permanent sterilant in this species.
Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil.
Ana Katharyne F
AK
Fagundes
Department of Veterinary Medicine, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil.
Erika C S
EC
Oliveira
Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil.
Bruno M
BM
Tenorio
Northeastern Biotechnology Network (Renorbio), Recife, Pernambuco, Brazil.
Cibele C S
CC
Melo
Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil.
Lorena T B
LT
Nery
Laboratory Keizo Asami, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
Fábio André B
FA
Santos
Laboratory Keizo Asami, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
Luiz Carlos
LC
Alves
B.E.T.Labs, Lexington, Kentucky, USA.
Robert H
RH
Douglas
Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil. Electronic address: valdemiroamaro@gmail.com.
Valdemiro A
VA
Silva
D000818:Animals; D002369:Castration / Q000379:methods / Q000662:veterinary*; D002415:Cats / Q000502:physiology*; D003267:Contraception / Q000379:methods / Q000662:veterinary*; D003272:Contraceptive Agents, Male / Q000009:adverse effects / Q000627:therapeutic use*; D005942:Gluconates / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D046529:Microscopy, Electron, Transmission; D013091:Spermatogenesis / Q000187:drug effects*; D013737:Testis / Q000187:drug effects* / Q000648:ultrastructure; D013739:Testosterone / Q000097:blood
D003272:Contraceptive Agents, Male; D005942:Gluconates; D013739:Testosterone; C030691:gluconic acid
Cat; Chemical castration; Infertility; Spermatogenesis; Zinc gluconate