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L. A. KRAFT and A. D. JOHNSON

Summary.

After unilateral separation of the rat epididymis from the testis, the metabolism of various substrates in vitro by tissue from the attached and separated caput and cauda epididymidis at 7 and 28 days after surgery was determined by radiorespirometry. Hourly collections of 14CO2 were made during 5-hr incubations. The patterns of 14CO2 evolution from glucose indicated that most of the metabolic activity followed the Embden-Meyerhof glycolytic and the Krebs cycle respiration pathways. The alteration of the rate of glycolysis was always greater than that of respiration. In all samples, the metabolism of [2-14C]glucose was approximately equal to that of [6-14C]glucose (G-6) and less than that of [1-14C]glucose (G-1). Pentose cycle activity was indicated in all tissues from the caput and cauda epididymidis by the preferential utilization of G-1 over G-6. At 7 and 28 days after surgery, respectively, the G-1 :G-6 ratios of 14CO2 evolution after incubation for 2 hr were 9·75 and 7·79 for the separated caput, 5·17 and 2·66 for the intact caput, 3·11 and 2·52 for the separated cauda and 3·73 and 2·84 for the attached cauda epididymidis. Although epididymal separation did not affect the metabolism of [U-14C]glucose or [U-14C]fructose, glucose appeared to be a more important epididymal substrate than fructose.

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T. T. TURNER and A. D. JOHNSON

Summary.

The epididymides of five mature bulls were unilaterally isolated by ligation at the efferent ductules. After 1 month's delay and electroejaculation to ensure sperm clearance of the isolated epididymis, the epididymides were removed, divided into five segments and subjected to a radio-respirometric study. The metabolism of [1-14C]glucose (G-1), [2-14C]glucose (G-2), [3,4-14C]glucose (G-3,4), [6-14C]glucose (G-6), and uniformly labelled glucose (G-U) and fructose (F-U) by normal and spermatozoa-free bovine epididymal tissue in vitro was determined.

The patterns of 14CO2 evolution were consistent with the Embden-Meyerhof and Krebs' cycle pathways of glucose metabolism, but utilization of G-1 exceeded G-6 throughout all zones. The mean G-1:G-6 ratio was 3·4 in control and treatment tissues which indicated a high rate of pentose-cycle activity. There was a significantly higher utilization of all substances by the control tissues over the treatment tissues. The F-U was utilized less than any of the labelled glucose substrates.

Zone 3 (corpus epididymidis) of treatment and control tissues used substrates at a higher rate than any other zone. Zone 3 was also noted for its high rate of pentose-cycle activity giving rise to speculation about possible synthetic activity. Zone 5 (cauda epididymidis) was the least metabolically active of all the zones studied.

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A. D. JOHNSON and M. B. SIGMAN

The location of cadmium (Cd) has been demonstrated in the testis of the mouse 16 days after injection (Berlin & Ullberg, 1963) and in the testis of the rabbit and guinea-pig 1½ hr after injection (Skold, 1961). The arrival of 109Cd in the testis of the rat and the domestic fowl as early as 2½ min after injection has been found (Johnson & Miller, 1970).

The damaging effect of Cd in the mammalian testis and the absence of such an effect in the avian testis has been recently reviewed by Gunn & Gould (1970). This differential effect raises the question of whether location of Cd is different in the testes of these two groups of animals. In attempting to answer this question, the location of 115mCd in the

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M. H. SLOAN and A. D. JOHNSON

Rabbit oviduct secretions have been analysed following ligation (David, Brackett, Garcia & Mastroianni, 1969), flushing (Olds & VanDemark, 1957) or cannulation of the genital tract (Holmdahl & Mastroianni, 1965). Data obtained from ligation have been questioned because of possible occlusion of the blood supply and histological damage. Flushing has the limitation of one sample per animal, so that any change with treatment or stage cannot be verified. This study was designed to determine if the secretions of a cannulated oviduct differ from those of the intact oviduct of the same individual.

A 6 cm-long silastic cannula (1·57 mm i.d., 2·4 mm o.d.) was inserted through a mid-ventral incision into the fimbriated end of one oviduct of each of twenty virgin does. The cannula was surrounded by a velour cuff 2 mm wide placed 1 cm from the tip. About three stitches were taken into

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A. D. JOHNSON and W. J. MILLER

Summary.

Male rats and domestic fowl were injected with 109Cd. After anaesthesia, blood was taken from the exposed heart and also various tissues were taken. The level of 109Cd was determined in each tissue.

In rats injected subcutaneously, there was a steady increase in the level of 109Cd for 40 min, followed by a drop in the whole testis, seminal vesicles, epididymis, skeletal muscle, heart, spleen, pancreas and liver. In the blood, the maximum level of 109Cd was reached at 10 min and dropped rapidly. In the ileum, duodenum, and kidney there was an increase for 80 min.

In most tissues of the intraperitoneally-injected rats, 109Cd reached the highest level at 2·5 min and tended to decrease thereafter. The amount of 109Cd in the blood reached a peak at 5 min and then dropped. Liver levels rose continually, while in the kidney, ileum and duodenum, levels rose for 40 min, then tended to drop.

In most tissues of the fowl, including the blood, the level of 109Cd rose gradually and dropped gradually. Levels in the kidney and liver showed a continual increase.

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A. D. JOHNSON and G. P. WALKER

Summary.

Carbonic anhydrase (CA) activity in the testis of the rat and fowl was inhibited in vivo and in vitro by cadmium chloride (CdCl2). Testes were removed from control animals and from animals which had previously received injections of 0·03 mmol CdCl2/kg. In both species, there was an initial inhibition followed by an increase in enzyme activity 10 min after injection. Exposure of testis tissue in vitro to 0·0001, 0·001, 0·01 or 0·1 m-CdCl2 revealed that the CA activity in the testis tissue of both species was equally inhibited. The data verify that cadmium causes biochemical changes in the testis soon after injection. The fact that testicular CA activity in both the rat and fowl is inhibited by Cd, suggests either that inhibition of this enzyme is not the mode of action resulting in testicular damage or that the fowl testis is tolerant to CA inhibition.

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T. T. TURNER and A. D. JOHNSON

Summary.

The epididymides of five mature bulls were unilaterally ligated at the efferent ductules, divided into five zones and subjected to a radiorespirometric study. The metabolism in vitro of [1-14C]acetate (A-1), [1-14C]pyruvate (P-1), [1-14C]lactate (L-1), [1-14C]succinate (S-1), and [1-14C]glucose (G-1) was determined for normal and spermfree bovine epididymal tissue.

The relationship of 14CO2 evolution among the substrates was as follows: P-1 > L-1 > S-1 > A-1 > G-1. The data showed that utilization of Krebs' cycle intermediates proceed at a greater rate than utilization of glucose. There was a significantly higher (P<0·01) 14CO2 evolution by the control tissues than the treated tissues. Zone 3 of both the treatment and control epididymides utilized more individual substrates at a significantly higher (P<0·05) rate than any other zone.

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R. R. EVANS and A. D. JOHNSON

III. CHOLESTEROL AND ESTERIFIED CHOLESTEROL METABOLISM

Department of Animal Science, University of Georgia College of Agriculture, Athens, Georgia 30602, U.S.A.

(Received 22nd August 1974)

The maturation process which spermatozoa undergo in the epididymis may be partly attributed to a synthesis in vivo of products used in this maturation (Turner & Johnson, 1973a). Scott, Wales, Wallace & White (1963) reported that glycerylphosphorylcholine (GPC) synthesis occurred in the caput and cauda epididymidis of the rabbit both in vivo and in vitro. Hamilton, Jones & Fawcett (1969) reported synthesis in vitro of cholesterol from acetate in the mouse epididymis and ductus deferens. Hamilton & Fawcett (1970), utilizing the rat epididymis and ductus deferens, showed synthesis in vitro of cholesterol and testosterone from acetate. Turner & Johnson (1971) reported that, with the removal of spermatozoa from an area of the epididymis, lipid fractions tended to increase in concentration and free cholesterol as a percentage

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M. A. KRAMEN and D. C. JOHNSON

Departments of Obstetrics and Gynecology and Physiology, University of Kansas Medical School, Kansas City, Kansas, U.S.A.

(Received 26th June 1974)

There has been little success in inducing a decidual reaction in the uteri of adult female rats given androgen neonatally. Burin, Thevenot-Duluc & Mayer (1963) reported a positive reaction after scratching the antimesometrial lining and giving progesterone (5 mg) daily for 8 days, but the incidence of success, the age of the animals, and the criteria for decidualization were not given. Barraclough (1967) reported that 25% of adult females given HCG to induce ovulation, and reserpine to sustain pseudopregnancy, produced a positive decidual reaction. All other reports are negative. The reasons for failure are not clear. Lack of oestrogen-binding capacity has been documented (McGuire & Lisk, 1969) and may play an important rôle; the availability of progesterone receptors in the uteri of such females is unknown.

In the present study,

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T. T. TURNER and A. D. JOHNSON

The total lipid content of spermatozoa during several stages of maturation has been studied by Grogan, Mayer & Sikes (1966) in the boar, by Setchell, Scott, Voglmayr & Waites (1969) in the ram, and by Lavon, Volcani & Danon (1970) in the bull. These authors have noted a general decrease of total lipid as spermatozoa undergo maturation. Scott, White & Annison (1961) analysed volatile fatty acids and long chain free fatty acids of ejaculated spermatozoa from the bull, ram, rabbit, fowl, dog, stallion and man. Their conclusion was that long chain free fatty acid and volatile fatty acid concentrations were too low to be of any value to the sperm cell after ejaculation. These authors did not investigate the levels or possible uses of fatty acids before ejaculation. In a later report, Scott, Voglmayr &