Isolation of Cerebral Capillaries from Fresh Human Brain Tissue

Understanding blood-brain barrier function under physiological and pathophysiological conditions is critical for the development of new therapeutic strategies that hold the promise to enhance brain drug delivery, improve brain protection, and treat brain disorders. However, studying the human blood-brain barrier function is challenging. Thus, there is a critical need for appropriate models. In this regard, brain capillaries isolated from human brain tissue represent a unique tool to study barrier function as close to the human in vivo situation as possible. Here, we describe an optimized protocol to isolate capillaries from human brain tissue at a high yield and with consistent quality and purity. Capillaries are isolated from fresh human brain tissue using mechanical homogenization, density-gradient centrifugation, and filtration. After the isolation, the human brain capillaries can be used for various applications including leakage assays, live cell imaging, and immune-based assays to study protein expression and function, enzyme activity, or intracellular signaling. Isolated human brain capillaries are a unique model to elucidate the regulation of the human blood-brain barrier function. This model can provide insights into central nervous system (CNS) pathogenesis, which will help the development of therapeutic strategies for treating CNS disorders

Characterization of the hair coat of the Polish Konik and Hucul pony focusing on the physical features and histological structure of different hair types

Celem badań była analiza porównawcza okrywy włosowej konika polskiego i konia huculskiego, ze szczególnym uwzględnieniem budowy histologicznej oraz parametrów fizycznych włosów. Włosy do badań pochodziły od 20 klaczy, po 10 z każdej rasy. Próby włosów zostały pobrane w okresie zimowym, z boku kłody, grzywy, ogona oraz szczotek. Włosy z boku kłody zostały podzielone na frakcję pokrywową i puchową. U obu ras zaobserwowano większy procentowy udział włosów puchowych (ok. 70%) w stosunku do włosów pokrywowych (ok. 30%). Włosy pokrywowe konika polskiego były o ok. 50% dłuższe w porównaniu do włosów konia huculskiego, natomiast długość włosów puchowych nie różniła się istotnie pomiędzy rasami. Zarówno włosy pokrywowe, jak i puchowe konika polskiego były o ok. 25% grubsze w porównaniu do włosów konia huculskiego. Zdolność do wydłużenia poszczególnych rodzajów włosów nie różniła się istotnie pomiędzy rasami. Najmniejsze wydłużenie (ok. 45%) stwierdzono dla włosów szczotek, natomiast największe (ok. 55%) – dla włosów grzywy. Budowa histologiczna kutikuli włosów nie wykazała różnic między analizowanymi rasami koni.The aim of the study was a comparative analysis of the hair coat of the Polish Konik and Hucul pony, focusing on the histological structure and physical parameters of the hair. Hair samples were obtained from 20 mares—10 of each breed. They were collected in winter, from the side of barrel, the mane, the tail, and front and rear fetlock. The hairs from the barrel were divided into overhair and underhair fractions. A higher percentage of underhair (about 70%) as compared to overhair (30%) was noted in both breeds. The overhair of the Polish Konik was about 50% longer than that of the Hucul pony, while the length of underhair did not differ between breeds. Both the overhair and the underhair of the Polish Konik were about 25% thicker than that of the Hucul pony. Elongation of particular types of hair did not differ significantly between the breeds. It was lowest for fetlock hair (about 45%) and highest for mane hair (about 55%). The histological structure of the cuticle layer of the hair did not differ between breeds

7-Nitroindazole Enhances Amphetamine-Evoked Dopamine Release in Rat Striatum. An in Vivo Microdialysis and Voltammetric Study

The intracellular second messenger nitric oxide (NO) is implicated in a variety of physiological functions, including release and uptake of dopamine (DA). In the described study, in vivo microdialysis and differential pulse voltammetric techniques were used to determine the involvement of NO in release of DA and its metabolites (dihydroxyphenylalanine, DOPAC; homovanillic acid, HVA) in neostriatum of freely moving rats. While the NO donor molsidomine (30.0 mg/kg; MOLS) and neuronal NO synthase- (nNOS-) inhbitor 7-nitroindazole (10.0 mg/kg; 7-NI) had no effect on the basal in vivo microdialysate level of DA, 7-NI specifically enhanced D,L-amphetamine- (1.0 mg/kg i.p.; AMPH) evoked release of DA. Basal or AMPH effects on DOPAC and HVA levels were not influenced by MOLS or 7-NI. Findings indicate that nitrergic systems have an important role in mediating effects of AMPH on dopaminergic systems