A direct effect of alpha-chlorohydrin on rat epididymal spermatozoa

The effect of alpha-chlorohydrin (alpha-CH) on rat epididymal spermatozoa was studied in vivo and in vitro. Alpha-CH was injected sc in doses of 5 and 20 mg daily for 16 days. The 20 mg dose resulted in diminished epididymal spermatozoal content (8 +/- 4 vs. 44 +/- 5 million, m +/- SE, n = 5) and motility (13 +/- 7 vs. 74 +/- 4%) as compared to saline injected-controls. Fertility rates were significantly reduced; control-100% (5/5), 5 mg - 25% (1/4), 20 mg - 0% (0/4). Alpha-CH was added to suspensions of spermatozoa in vitro and a level of 132 micrograms/ml depressed motility by 90% (P less than 0.0001) and O2 consumption by 40% (P less than 0.05). Intrauterine insemination of in vitro treated spermatozoa was performed in 61 pro-oestrous rats. Alpha-CH treated spermatozoa (from 5.3 to 26.400 micrograms/ml) were found to be completely infertile compared to untreated spermatozoa which showed a 63% fertility rate. There was almost complete absence of oocytes in the flushed ampullas of recipients of alpha-CH treated sperm, in the lowest dose which did not affect sperm motility. Thus, alpha-CH has direct effect upon spermatozoal function and also has a possible effect on the female reproductive tract.

Activities of various 6-chloro-6-deoxysugars and (S) alpha-chlorohydrin in producing spermatocoeles in rats and paralysis in mice and in inhibiting glucose metabolism in bull spermatozoa in vitro

6-Chloro-6-deoxyglucose, 6-chloro-6-deoxymannose, 6-chloro-6-deoxy-fructose, 6-chloro-6-deoxyglucitol, 6-chloro-6-deoxygalactose and (S) alpha-chlorohydrin all produced spermatocoeles in the ductuli efferentes and epididymis of the rat and were neurotoxic in the mouse, but only alpha-chlorohydrin caused substantial inhibition of glucose metabolism in bull spermatozoa in vitro. The relative potencies of the compounds in producing spermatocoeles reflected their activities as reversible antifertility agents in the rat but compared to the others 6-chloro-6-deoxymannose was considerably less neurotoxic to mice than might have been anticipated from its contraceptive dose. Thus different metabolites may be responsible for causing the antifertility and the neurotoxic effects.

Inhibition of fructolysis in boar spermatozoa by the male antifertility agent (S)-alpha-chlorohydrin

The (S)-isomer of the male antifertility agent alpha-chlorohydrin strongly inhibited the oxidative metabolism of fructose by boar spermatozoa in vitro. The result of this action, which has been deduced to be an inhibition of glyceraldehydephosphate dehydrogenase, caused an accumulation of fructose-1,6-bisphosphate and the triosephosphates, and a decrease in substrate-level phosphorylation with a concomitant lowering of the energy charge potential of the spermatozoa. The (R)-isomer of alpha-chlorohydrin had no inhibitory activity on fructolysis. A study of the comparative metabolism of (R)-[3-36Cl]-alpha-chlorohydrin and (R,S)-[3-36Cl]-alpha-chlorohydrin by boar spermatozoa showed that it is the (S)-isomer that specifically undergoes a process of oxidative metabolism to (R)-3-chlorolactaldehyde. It is proposed that this endogenous oxidation product, which has the same absolute configuration as the substrate for glyceraldehyde-phosphate dehydrogenase, is the active metabolite of (S)-alpha-chlorohydrin that inhibits this enzyme. Exogenous (R,S)-3-chlorolactaldehyde inhibited the oxidative metabolism of fructose by boar spermatozoa, apparently by a mechanism similar to that of (S)-alpha-chlorohydrin.

Mutagenicity of glycerol chlorohydrines and of their esters with higher fatty acids present in protein hydrolysates

3-chloro-1,2-propanediol and 1,3-dichloro-2-propanol caused base substitutions in Salmonella typhimurium TA1535 both with and without metabolic activation. Metabolic activation seemed to act mainly by decreasing the toxicity of these compounds. A difference in the growth of the wild-type and repair-deficient strains of Escherichia coli was observed only for 1,3-dichloro-2-propanol with S9 mix. Esters of both chlorohydrines with fatty acids has smaller mutagenic effects than unesterified compounds.

Effects of antifertility drugs on epididymal protein secretion, acquisition of sperm surface proteins and fertility in male rats

The possibility that alpha-chlorohydrin, 6-chloro-6-deoxyglucose (6CDG) and cyproterone acetate (CPA) might affect epididymal protein secretion or acquisition of sperm surface proteins as the cause of their antifertility action in male rats was investigated. Daily administration of 9 mg/kg alpha-chlorohydrin for 7--14 days and 24 mg/kg 6CDG for 14--21 days induced sterility in male rats and imparied the capacity of the cauda epididymal spermatozoa to initiate motility. Treatment with CPA (30 mg/kg/day) for 21--28 days, however, was found to have no effect on fertility and initiation of sperm motility, although the epididymis of the treated animals underwent a loss in weight. The antifertility effects of alpha-chlorohydrin or 6CDG did not seem to be attributed to an interference with epididymal protein secretion. The cauda epididymal fluids of the alpha-chlorohydrin, 6CDG and CPA treated animals have similar protein patterns compared to those of the control animals. However, when the surface proteins of the spermatozoa were labelled with radioactive iodine, the sperm surface proteins alpha-chlorohydrin and 6CDG treated animals were found to differ from those of the control animals. Two peaks (MW 32 000 and 70 000) and one peak (70 000) were significantly reduced in the alpha-chlorohydrin treated and 6CDG treated animals, respectively. Additional bands appeared on the surface of the treated (infertile) animals. In contrast, CPA treatment did not affect the surface protein pattern of the epididymal spermatozoa. It was concluded that the antifertility affects of alpha-chlorohydrin and 6CDG are not due to an interference with epididymal secretion of specific proteins but to an intervention of the subsequent acquisition of these proteins by epididymal spermatozoa. This results in a decrease in the capacity of the epididymal sperm to initiate motility and hence a loss of fertilizing capacity.

The fate of oxalic acid in the Wistar rat

1. An established procedure for determining oxalate in human urine has been modified for rat urine. The daily excretion of oxalate by the male Wistar rat is 570-650 microgram. 2. Oxalate excretion in rat urine following i.p. administration of [14C]oxalic acid (1-70 mg/kg) has been studied. The rate and degree of excretion are dose-dependent. 3. The excretion of urinary oxalate by the rat has been quantified after administration of two oxalate-producing xenobiotics, alpha-chlorohydrin and 1,2-dibromo-3-chloropropane. 4. Oxalate inhibits the metabolism of glucose and lactate by isolated rat kidney tubules in vitro.

Effects of low doses of alpha chlorohydrin on the dehydrogenases and oxidases of rat epididymal epithelium and sperms: a correlative histochemical and biochemical study

Histochemical studies have been made of the isocitrate dehydrogenase, succinic dehydrogenase, malate dehydrogenase, glutamate dehydrogenase, DPN diaphorase, TPN diaphorase, delta 5-3 beta-hydroxysteroid dehydrogenase and monoamine oxidase in the caput, corpus and cauda epididymides of normal and alpha chlorohydrin (6.5 mg/kg/9 days) treated rats. Administration of alpha chlorohydrin in a low dose caused a conspicuous decrease in all these enzymes except delta 5-3 beta-HSD, in various cell types of epididymal epithelium and sperms. Biochemical estimations of isocitrate dehydrogenase, succinic dehydrogenase, malate dehydrogenase and delta 5-3 beta-HSD have further supported and confirmed these histochemical observations. These changes in enzyme activities after treatment with low dose of alpha chlorohydrin strongly suggest that TCA cycle and amino acid metabolism of epididymis become defective, much earlier before any histological damage to the epididymis becomes visible.

Effect of low doses of alpha chlorohydrin on the enzymes of glycolytic and phosphogluconate pathways in the rat testis and epididymis

A biochemical study has been made of the effects of low doses of alpha chlorohydrin on all the glycolytic enzymes and two key enzymes of phosphogluconate pathway i.e. glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH) of rat testis and epididymis. All the glycolytic enzymes of testis and epididymis are decreased after treatment with alpha chlorohydrin. G-6-PDH and 6-PGDH are decreased only in epididymis and not in the testis. LDH, ADH and glucose-6-phosphatase were also studied histochemically to show that the drug affects the glycolytic enzymes of epididymal cells and various testicular cell types of testis. Possible significance of these results is discussed.

Inhibition of glycolysis in boar sperm by alpha-chlorohydrin

The effect of alpha-chlorohydrin (3-chloropropan-1,2-diol) on the metabolism of D-[U-14C]-fructose and L-[U-14C]-lactate by washed boar sperm has been investigated. Whereas alpha-chlorohydrin at concentrations as low as 0.1 mM inhibited the metabolism of fructose and led to an increase in the utilization of endogenous lactate, amounts up to 500 mM had no effect on the oxidation of added lactate. Low levels of alpha-chlorohydrin increased the cellular concentrations of fructose-1,6-bisphosphate and the triosephosphates, an effect consistent with the inhibition of glyceraldehyde-3-phosphate dehydrogenase. Although [U-14C]-glycerol was rapidly oxidized by boar sperm, [U-14C]-alpha-chlorohydrin was not metabolized to 14CO2, showing that it is not converted to glycerol. Extracts obtained by sonication of boar sperm after incubation with [3-36C1]-alpha-chlorohydrin, did not contain [3-36C1]-alpha-chlorohydrin-1-phosphate. This is contrary to the postulate that this phosphorylated compound is the inhibitory metabolite of alpha-chlorohydrin.

Inhibition of spermatogenesis in house rat (Rattus rattus Rufescens) following the administration of alpha- chlorohydrin

Chronic administration of alpha-chlorohydrin (25 mg/kg body wt.) caused lesions in the testis of house rat. The changes in the germ cells were degenerative. The seminiferous tubules and Leydig cell nuclear diameter were reduced. Epididymal cell height was greatly reduced. The lumen was devoid of spermatozoa. alpha-Chlorohydrin administration inhibited the synthesis of RNA, protein, sialic acid in the testis and accessory sex organs. Total cholesterol of the testis was increased. Adrenal ascorbic acid depletion was conspicuous. alpha-Chlorohydrin anatagonizes the stimulatory action of testosterone in castrated house rats. alpha-Chlorohydrin can be considered as a biologically effective compound for the control of house rat population in human dwellings. It's dose dependent reaction is discussed.

Antifertility and toxicological studies with aromatic esters of alpha-chlorohydrin in male rats

Due to the drawbacks in the potential use of alpha-chlorohydrin itself as a male oral contraceptive, two novel crystalline derivatives, alpha-chlorohydrin-bis-m-nitrobenzoate and alpha-chlorohyrdin-mono-p-acetamidobenzoate, were synthesized and tested for antifertility activity in male rats. In addition, the nephrotoxic effects of alpha-chlorohydrin itself and of the two aromatic esters were investigated by the use of diuretic experiments, plasma biochemical analyses and kidney histology. Both esters were found to be of comparable molar potency to alpha-chlorohydrin in inducing temporary infertility following daily oral administration. The nephrotoxic effects following high oral doses of alpha-chlorohydrin were largely eliminated by the use of either ester. These derivatives have several advantages over alpha-chlorohydrin, being crystalline compounds of definable purity. Although potency was retained, acute oral toxicity was greatly reduced, due to a combination of factors - the esters were poorly absorbed in high dosage whilst relatively slow breakdown permitted effective levels to be attained on epididymal spermatozoa.

Effect of alpha-chlorohydrin on glucose metabolism by spermatozoa from the cauda epididymidis of the rhesus monkey (Macaca mulatta)

Spermatozoa from the cauda epididymidis of the rhesus monkey had metabolic properties similar to those published for ejaculated spermatozoa. The concentration of glycolytic intermediates was low until 2 mM-glucose was added; glucose 6-phosphate, fructose 1,6-bis-phosphate and the triose plhosphates then increased but glycerate 3-phosphate did not. It was concluded that the activity of glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12) limited flux through the glycolytic pathway. The production of lactate and CO2 from glucose was strongly inhibited in the presence of 5 or 10 mM-alpha-chlorohydrin. The energy charge of the spermatozoa was low before and after 1 incubation with 2 mM-glucose (0.5 +/- 0.05 and 0.05 +/- 0.06 respectively) and the value after the incubation was decreased in the presence of 5 or 10 mM-alpha-chlorohydrin (0.17 +/- 0.05 and 0.15 +/- 0.04 respectively). alpha-Chlorohydrin inhibited glycolysis at the glyceraldehyde 3-phosphate dehydrogenase reaction.

The epididymal microenvironment: a site of attack for a male contraceptive?

During their development, spermatozoa are continually bathed in fluid provided by epithelial secretions of the seminiferous tubule and the epididymal duct. This fluid or microenvironment is probably very important for spermatozoal maturation and survival. Micropuncture and microanalytic studies have revealed the occurrence of several biochemical changes of this specialized microenvironment along the epididymal duct; these changes seem to be linked to sperm maturation. The interactions between maturing spermatozoa and their microenvironment must be understood before interference in sperm maturation through intervention of the formation of the microenvironment is possible. Several compounds have been shown to interfere in spermatozoal maturation in the epididymis although their use as male contraceptives requires further investigation.

The response of the male domestic fowl (Gallus domesticus) to alpha-chlorohydrin treatment

Sexually mature male cockerels were treated with low and high doses of alpha-chlorohydrin for up to 30 days. Neither gross nor histological lesions were produced by the drug, and sodium, potassium and acid phosphatase levels in the testicular fluid and ductus deferential plasma were not significantly altered. All the cockerels given low doses remained fertile.

Studies on the mechanism of action of alpha-monochlorohydrin

After a single oral dose of 100 mg/kg of alpha-chlorohydrine, two distinct phases in the response of the testes to the treatment have been observed: (i) the immediate onset of testicular swelling lasting up to five days, accompanied with a steady increase in the weight of the testes and (ii) thereafter a constant decrease in the testes weight. Changes in the diameter of the seminiferous tubules and the thickness of the basement membrane were observed after the administration of the drug. Multinucleated giant cells were encountered 5 days after drug administration. Alkaline phosphatase, SDH, nucleic acids and proteins showed a fall after treatment with the drug. On the contrary, cholesterol, phospholipids and glycogen showed an increase after its administration. Acid phosphatase showed a fall in the initial stages only, but the activity was higher after 10, 20 and 40 days of the treatment with the drug. The level of plasma and testes testosterone remained normal after chlorohydrin administration. The induction of lesions in hypophysectomised gonadotropin-stimulated animals suggests that the action of chlorohydrin is not mediated through gonadotropins. Alpha-chlorohydrin administered intratesticularly did not evoke any changes in the histo-architecture of the testis.

Response of scrotal and non-scrotal vertebrate testis to the male antifertility agent alpha-chlorohydrin

Effect of single oral dose (90 mg/kg body weight), multiple doses (90 mg/kg body weight for 7 days) or even higher doses (180-300 mg/kg body weight) of alpha-chlorohydrin on the testis-epididymis complex of dog, rat, cryptorchid rat, hedgehog, domestic fowl, lizard, frog, and toad has been studied. alpha-chlorohydrin treatment, at any dose, did not induce lesions in the testis-epididymis complex of dog and hedgehog having testis in scrotum and inguinal canal respectively. Abdominal testis of cryptorchid rat, domestic fowl, lizard, frog and toad also did not respond to alpha-chlorohydrin treatment. Lesions in normal rat testis-epididymis complex, after single oral dose of alpha-chlorohydrin, were quite prominent. Non-sensitivity of alpha-chlorohydrin to these animal species may be due to the absence of the pampiniform plexus complex in hedgehog and sub-mammalian animal species. Absence of conventional epididymis in the sub-mammalian animal species may be the additional reason of the non-sensitivity of the drug. Prominence of collateral blood vasculature in dog testis-epididymis complex and some alterations in the blood supply due to cryptorchidity in cryptorchid rat testis seems to be the reason of non-sensitivity of alpha-chlorohydrin to dog and cryptorchid rat testis. These observations confirm the hypothesis that the action of a single oral dose of alpha-chlorohydrin is associted with the blood vasculature of the testis-epididymis complex.

Effect on gonadotrophin secretion of blockage of the ductuli efferentes in the normal and androgen-deprived rat

Serum LH and FSH concentrations were measured in adult male rats. Blockage of the ductuli efferentes by surgical ligation or treatment with the anti-fertility drug alpha-chlorohydrin did not produce any changes in serum LH or androgen-dependent organ weights. Serum FSH in both groups was significantly raised by 4 days after treatment and remained so throughout most of the experimental period (42 days) but did not attain the values obtained in castrates. The gonadotrophin changes were accompanied by an initial increase in the weight and turgidity of the testes which then became flaccid and atrophied. These changes were similar but not identical after both treatments. Androgen secretion was impaired in adult rats treated with ethylene dimethane sulphonate; serum LH values were similar to those of 14-day castrates, and serum FSH was also elevated but not to the level found in the castrates. Ligation of the ductuli efferentes did not produce any further changes in concentrations of either hormone in spite of the retention of the testicular products within the testes as reflected by an increase in weight. The results are consistent with the view that changes in serum FSH after blockage of the ductuli efferentes are related to disturbances in the production of inhibin from the seminiferous epithelium rather than retention of inhibin with the testicular tubules.

Agonistic properties of low doses of antifertility compounds in male rats

Male Wistar Strain rats of known fertility were given subcutaneous dosage of three drugs, alpha-chlorohydrin, amino-alpha-chlorohydrin, and busulphan alone or in combination for a period of thirty days. Males were housed overnight with females at various times during the treatment and ninety days after cessation of treatment. There were significant differences in levels of glycerylphosphorylcholine in the epididymides of two treatment groups as well as differences in numbers of spermatozoa recovered from the reproductive tracts of female rats mated with males from four treatment groups. Treatment had no effect on the weights of the testes or sex accessory organs or sialic acid levels in the epididymis, fructose levels in dorso-lateral prostate and coagulating gland, or citric acid levels in seminal vesicle and ventral prostate of the treated males when compared to controls. The antifertility activity was probably mediated by an effect on epididymal spermatozoa and thereby subsequent change in sperm transport within the female genital tract.

The interaction of alpha-chlorohydrin with glycerol kinase

alpha-Chlorohydrin has been examined both for its ability to act as a substrate for glycerol kinase and as an inhibitor of the reaction of glycerol with glycerol kinase. Using a purified enzyme from Candida mycoderma, it was established that alpha-chlorohydrin does not act as a substrate for glycerol kinase, but does act as a competitive inhibitor (Ki of 30 mM) of purified glycerol kinase and the enzyme present in a sonicated preparation of ram spermatozoa. Neither alpha-chlorohydrin nor alpha-chlorohydrin phosphate acted as inhibitors of NAD- or flavin-linked glycerolphosphate dehydrogenase. It is concluded that alpha-chlorohydrin does not cause the impairment of sperm metabolism as a result of phosphorylation catalysed by glycerol kinase.