The effect of changes in thyroid function on the action of autonomic drugs upon the secretion of saliva by the submaxillary glands was studied in male Wistar rats. Hyperthyroidism was induced by the sc administration every 12 h of 10 micrograms/100 g bw of L-triiodothyronine; hypothyroidism was induced by surgical thyroidectomy 2 weeks before the experiments. The dose-response curves to increasing doses of isoprenaline, norepinephrine or methacholine showed in hyperthyroid animals increased salivary secretion, while in hypothyroid animals the dose-response to the drug was reduced. The threshold dose for isoprenaline was reduced in hyperthyroid animals and increased in hypothyroid ones. The threshold dose for norepinephrine did not change in hyperthyroid or hypothyroid animals while that for metacholine was decreased in hyperthyroid ones. When norepinephrine was given to alpha-blocked animals (with phentolamine) the difference in the dose-response curves between hyperthyroid and control animals was increased. But when norepinephrine was given to beta-blocked animals (with propranolol) the difference between the dose-response curves of hyperthyroid and control animals disappeared. The results above presented show that the sensitivity of the submaxillary salivary glands of rats to some adrenergic and cholinergic drugs was altered by the thyroid hormone. The effect was greater in the responses mediated by beta receptors. The structural changes in these glands may have some role in these effects.

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SUMMARY The effects of castration, and of the daily administration of 100 or 300 μg testosterone propionate (TP) for 1 month to castrated animals, on the glycosaminoglycans of the ventral prostate, seminal vesicles and salivary glands, were studied in male white rats. Castration produced atrophy of the ventral prostate and seminal vesicles together with increased concentration of uronic acid, and atrophy of the submaxillary glands together with decreased uronic acid concentration. The administration of TP to castrated animals produced opposite effects. No changes in weight or in uronic acid concentration were found in the parotid and retrolingual glands. Fractionation on cellulose microcolumns showed that the changes in uronic acid concentration were due to changes in fraction 1 (glycoproteins) in the submaxillary glands, in fractions 2 (hyaluronic acid) and 3 (heparitin sulphate) in the seminal vesicles, and in all the chromatographic fractions in the ventral prostate.

Sialic acid was assayed in hypertrophic submaxillary and retrolingual glands after periodic incisor amputations. In the submaxillary glands, an increased sialic acid concentration and total content was found. In the retrolingual glands, the sialic acid concentration did not change, but total content of the acid increased.Sialic acids are important components of salivary-gland mucins.1,2 By means of histochemical3-5 and chemical methods,3'6 their presence has been detected in most mammalian salivary glands. In rats and mice, a great sialic acid concentration has been shown in retrolingual glands, a moderate concentration in the submaxillary glands, and a low concentration in the parotid glands.3'7,8 Different hormonal and nervous factors modify the sialic acid concentration of the salivary glands. Thus, castration in male mice increased sialic acid concentration of submaxillary glands and decreased retrolingual and plasmatic sialic acid concentration, whereas opposite results were obtained when testosterone proprionate was administered to castrated mice.9 However, the administration of isoproterenol increased sialic acid concentration and total content in submaxillary glands, did not change the sialic acid concentration and total content of retrolingual glands, and increased plasmatic sialic acid concentration.8Repeated incisor amputations produced decided hypertrophy of the submaxillary'0-'2 and retrolingual glands""12 in the rat, but

Adrenalectomy decreased sialic acid content in the submaxillary and retrolingual glands of normal male rats. The administration of cortisol acetate to adrenalectomized rats increased submaxillary and retrolingual sialic acid content; administration of desoxycorticosterone acetate decreased the submaxillary gland content but not the retrolingual gland content.Sialic acids are important components of salivary gland mucins.1,2 In rats, a high sialic acid content has been demonstrated in the retrolingual glands; moderate content has been demonstrated in the submaxillary glands, and low content in the parotid glands.3-5The administration of isoproterenol to rats increased sialic acid concentration in the hypertrophic submaxillary glands, but it had no effect on the size and sialic acid concentrations of the retrolingual glands.5 Periodic incisor amputations produced submaxillary and retrolingual gland hypertrophy in rats, but the sialic acid concentration was increased only in the submaxillary glands.6 Parasympathetic denervation produced submaxillary and retrolingual gland atrophy, but the sialic acid concentration was decreased only in the submaxillary glands.7There has been controversy about the influence of the adrenal glands on the structure of the salivary glands. of mice.8 On the other hand, adrenalectomy or the administration of glucocorticoids did not affect the structure of the parotid and retrolingual glands or the acinous portion of the submaxillary glands in rats.9 10 In this paper. the role of the adrenal glands on the sialic acid content of the submaxillary and retrolingual glands is reported. Materials and MethodsNinety male white rats were fed a routine laboratory diet in pellet form. Water was given ad libitum.In the first experiment, adrenalectomized rats were compared with sham-operated controls 20 days after the operation.In the second experiment, all the rats were adrenalectomized and separated into three subgroups: (1) those injected daily with the vehicle (water), (2) those injected daily with 100 /ig cortisol acetate, and (3) those injected daily with 300 ,ug cortisol acetate. This steroid was injected daily subcutaneously in an aqueous suspension during 20 days; each injection was in a 0.1 ml volume. The rats were autopsied 24 hours after the last injection. In the third experiment all the rats were adrenalectomized and separated into three subgroups: (1) those injected daily with the vehicle (olive oil), (2) those injected daily with 100 /ig desoxycorticosterone acetate, and (3) those injected daily with 300 jug of desoxycorticosterone acetate. This steroid was injected daily during 20 days, in an olive oil solution; each injection was in a 0.1 ml volume. The rats were autopsied 24 hours after the last injection.At the end of each experiment, the rats were killed by an overdose of chloral-morphine solution. Plasma was obtained from 1265 at MOUNT ALLISON UNIV on June 11, 2015 For personal use only. No other uses without permission.