Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The acquisition of conditioned avoidance responses along with spontaneous behaviors were studied in ovariectomized rats. Fourteen days after ovariectomy, they were injected subcutaneously with one of the following doses of estradiol benzoate: 0.2, 2 or 20 microgram/rat. Behavioral tests were applied 3, 24, 48 or 72 hours after estradiol treatment. Although estradiol 2 microgram/rat induced a decrease in acquisition of conditioned avoidance responses at all times tested, this effect was maximum at 48 h. Estradiol 0.2, and 20 microgram/kg decreased and stimulated, respectively, the acquisition performance, as tested 3 h after injection. All doses increased global motility and rearing behavior. This hypermotility disappeared at 24 h, but it was observed again at 48 and 72 h after estradiol 0.2 and 20 microgram/rat. The hormone also induced an increase in head shaking and a decrease in grooming. Although the behavioral changes are more significant in presence of very low serum levels of estradiol, they seem to be triggered by the previous increase in the estradiol levels. The possible sites and mechanisms of action of estradiol on behavior are discussed.
 ...
PMID:Effects of estradiol replacement in ovariectomized rats on conditioned avoidance responses and other behaviors. 194 32

1. Estrogens have been shown to decrease the effect of apomorphine in a variety of animal behavioral models reflecting the sensitivity of striatal and mesolimbic dopamine receptors. 2. These include circling, and locomotor activity, in rats and suppression of midbrain tremor as well as lingual dyskinesia in monkeys. 3. Estradiol also increases the haloperidol-induced catalepsy in rats. Moreover estradiol increases 3H spiroperidol specific binding in the rat striatum and potentiates the increase caused by haloperidol or denervation with 6-hydroxydopamine. 4. These findings point to an action of estradiol similar to a week neuroleptic. 5. Thyrotropin-releasing hormone when injected into the head of the caudate nucleus in cats induces a head turning response which may be ipsilateral or contralateral depending upon the injection site. The response is similar to the effect of dopamine injected into the same site. 6. The effect of dopamine but not that of TRH is blocked by prior administration of haloperidol indicating that although TRH has a dopamine-like action in the caudate nucleus, it is not mediated via the dopamine terminals or the dopamine receptors.
 ...
PMID:Estradiol, TRH and striatal dopaminergic mechanisms. 681

The biotransformation and bioconcentration of natural and synthetic steroid estrogens by Chlorella vulgaris were investigated by using batch-shaking experiments with incubation for 48 h in the light or dark. Estradiol and estrone were interconvertible in both light and dark conditions; however, this biotransformation showed a preference for estrone. In the light, 50% estradiol was further metabolized to an unknown product. Apart from biotransformation, estrone, as well as hydroxyestrone, estriol, and ethinylestradiol, was relatively stable in the algal culture, whereas estradiol valerate was hydrolyzed to estradiol and then to estrone within 3 h of incubation. All of the tested estrogens exhibited a degree of partitioning to C. vulgaris; however, the concentrations of estriol, hydroxyestrone, ethinylestradiol, and estradiol valerate were always below the quantification limits. For estradiol and estrone, the partitioning of these estrogens in the algal extracts to the filtrates was <6% of the total amount present. The average concentration factor for estrone was ca. 27; however, the concentration factor for estradiol was not reported since no equilibrium was reached between the aqueous solution and that within the cells due to continuing biotransformation.
 ...
PMID:Biotransformation and bioconcentration of steroid estrogens by Chlorella vulgaris. 1182 29