The mechanism of action of the alkaloid 1-(2´-bromine-4´,5´-dimethoxyphenyl) - 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (F-18) on the functional activity of smooth muscle cells of the rat aorta was studied. Isometric contraction activity was recorded using a Grass FT – 03 (Grass Instrument, USA) mechanotron. The relaxant effect of the F-18 alkaloid was found to be associated with blockade of Ca2 + (IP3R) channels in the SR, along with voltage- dependent and receptor-operated Ca2+channels in the aorta smooth muscle cell plasmalemma.
The article studies a capillary electrophoretic (CE) method for the analysis of urinary extracts of the local anesthetic, bupivacaine, and its three main metabolites, desbutylbupi vacaine, 3’ hydroxybupivacaine, and 4’-hydroxybupivacaine, in rat urine. After collection of blank urine, the rats were given a 20 mg/kg intramuscular injection of bupivacaine, and urine was collected for 12 h after dosing. CE analyses were performed using the CAPEL®-205 capillary electrophoresis systems. The data was collected using the Elforan® specialized software. The use of methanol to reduce peak tailing was investigated at different concentrations, but 20% and 30% v/v were proved to be the most optimal at the preparatory stage of the experiment. The resolution of 3’ hydroxybupivacaine and 4’-hydroxybupivacaine was 1.09, 0.98, 0.89 and 0.89 at 15, 40, 70 and 110 s, respectively. The initial resolution (Rs) of desbutylbupi vacaine was achieved with all studied injection periods as Rs = 1.09, 0.97, 0.96 and 0.96 at 15, 40, 70 and 110 s, respectively. Separation efficiencies for 3’- and 4’ hydroxybupivacaine were312×10 3 , 257×10 3 , 196×10 3 и 169×10 3 μlat injection times of15, 40, 70 and 110 s, respectively. The results showed that the mass of bupivacaine, desbutylbupi vacaine, and 3’- and 4’ hydroxybupivacaine significantly recovered in the rat urine after the dose was administered. The recoveries as a percent of the dose were 0.04, 0.80, 0.15 and 0.05% for desbutylbupi vacaine, bupivacaine, 3’-hydroxybupivacaine, and 4’-hydroxybupivacaine, respectively. Separation of bupivacaine and its metabolites was achieved in 15 min. A particular advantage of this approach over published HPLC methods is that separation of the two hydroxy positional isomers of bupivacaine is possible. A number of unknown peaks were also observed in the electropherograms from the rats dosed with bupivacaine. These did not correspond to any peaks appearing in the blank urine samples. Characterization of these unknown peaks may prove useful for the further understanding of bupivacaine metabolism.
Ионы Ca 2+ являются универсальным регулятором метаболических процессов. Одним из механизмов, регулирующих концентрацию ионизированного Са 2+ в цитозоле, является его транспорт в митохондрии. Известно, что тиреоидные гормоны влияют на активный транспорт ионов Са 2+ in vivo и in vitro. Можно полагать, что гормоны могут оказывать свое действие на метаболизм; изменяя распределение ионов Са 2+ между митохондриями и цитозолем.
The works show that, using fluorescent probes, it was used to study the effect of PC-8 on changes in the dynamics of the intracellular Ca2+ content in synaptosomes of the rat brain, depending on the site of the binding of glutamate on calcium channels by a specific mediator with glutamate. To measure the amount of cytosolic Ca2+ synaptosomes, we calculated using the Grinkevich equation. It has been shown that polyphenol PC-8 binds to the glutamate-binding site of NMDA receptors, so that the conductance for Ca2+ ions is reduced through a channel blocking the effect of polyphenol PC-8 can be explained. due to its binding to the competing action of the site, the binding of glutamate to NMDA receptors.
Тиреоидным гормонам принадлежит ведущая роль в обмене веществ, вследствие выраженного регулирующего влияния их на основные его функции . По нашим и литературным данным установлено, что тиреоидные гормоны секретируются в грудное молоко женщин и могут оказывать определённое воздействие на развивающийся организм новорождённых. В то же время, до настоящего времени в этом вопросе, нет окончательного мнения