Search PubMed⌕ Search

Biomedical subjects

J K Jones

Publications and source records attributed to J K Jones.

At least 91 records · Page 5Linked to original sources

Rat liver adenyl cyclase activity in various thyroid states.

Thyroidectomized and euthyroid rats were injected with three doses of triiodothyronine (T(3)) or of the diluent over a 6 day period, and liver homogenates were assayed for basal, epinephrine-stimulated, and NaF-stimulated adenyl cyclase activity. Based on NaF-stimulated levels, total adenyl cyclase activity, expressed per milligram of liver protein, was increased after thyroidectomy. Administration of T(3) to either hypothyroid or euthyroid rats, however, had no effect on the NaF-stimulated levels. Basal and epinephrine-stimulated enzyme activities were the same in hypothyroid, euthyroid, and hyperthyroid (euthyroid + T(3)) liver homogenates. In contrast, injections of T(3) in hypothyroid rats increased the activities of basal and epinephrine-stimulated adenyl cyclase. In view of the findings in euthyroid and hyperthyroid liver, it is possible that this effect is transient. In general, no correlation was found between the effects of thyroid hormone on respiration and on adenyl cyclase activity of the rat liver. These results imply that the hepatic thermogenic response to thyroid hormone is not mediated by stimulation of adenyl cyclase activity with the possible exception of the early effects of T(3) in the athyroid rat.

Adenylyl Cyclases↗

Macronyssid mites in oral mucosa of long-nosed bats: occurrence and associated pathology.

Macronyssid mites (Radfordiella) have been found in the oral mucosa of the long-nosed bat (Leptonycteris nivalis), which occurs from Texas southward throughout much of Mexico. This is the first report of mites of the suborder Mesostigmata attached in the oral cavity of a mammal. Osteolysis of hard palate and odontolysis of teeth result from infestations of mites adjacent to the upper premolars and molars; destruction of bone, teeth, and Connective tissue often leads to exfoliation of teeth in life. Oral mites have not been found in Leptonycteris sanborni, a species in part sympatric with Leptonycteris nivalis.

Animals↗