Maternal protein restriction affects cardiovascular, but not respiratory response to L-glutamate microinjection into the NTS of conscious rats.

Purpose: Dysregulation of glutamatergic neurotransmission (GN) is linked to sympathetic-respiratory overactivity and hypertension. We investigated whether maternal protein restriction is able to alter GN into the nucleus of the solitary tract (NTS) in adult offspring.Methods: Wistar rat dams were fed with control (NP; 17% protein) or low-protein (LP; 8% protein) diet during pregnancy and lactation, and their offspring were evaluated at 70-90d old. Direct measurements of mean arterial pressure (MAP), heart rate (HR), respiratory frequency (RF) and respiratory (RV) and cardiac (CV) variabilities were assessed in consciousness. The evaluation of GN into NTS over cardiovascular system were assessed by microinjections of unilateral glutamate (L-glu 0.5 nmol/100nL) and bilateral kynurenic acid (Kyn 2.5 nmol/50nL). The NP and LP groups were compared using unpaired Student's t-test where p < 0.05 was considered significant.Results: The LP exhibited higher MAP at rest (p = 0.03) and after L-glu microinjection (p = 0.04), as well as an increase over HR after Kyn microinjection when compared to the NP (p = 0.049). In the RV, the LP group showed an increase of the component-standard deviation 1 (p = 0.037) at rest. In the CV, the LP presented an increase of the low frequency (LF) component of the pulse interval (PI) (p = 0.034), a decrease of high frequency (HF) of the PI (p = 0.034), beyond an increased LF/HF ratio of the PI (p = 0.027) when compared to the NP. The kynurenic acid microinjection did not produce changes in RV or CV (p > 0.05).Conclusions: Altered GN into the NTS may contribute to augmented blood pressure in protein-restricted offspring.

Ferramentas analíticas aplicadas à caracterização de complexos de inclusão fármaco-ciclodextrina / Analytical tools applied to the characterization of drug - cyclodextrin inclusion complexes

As ciclodextrinas (CDs) têm sido bastante utilizadas no desenvolvimento de produtos farmacêuticos, particularmente devido às suas propriedades complexantes, a qual promove incremento na solubilidade de fármacos poucos solúveis. O ambiente lipofílico da cavidade interna das CDs propicia condições favoráveis para a formação de complexos de inclusão (CI) com compostos hidrófobos. Variações nas propriedades físico-químicas das moléculas hóspedes podem ser identificadas através de metodologias analíticas, que permitem detectar a formação dos complexos. O objetivo deste trabalho foi discutir os principais métodos utilizados na caracterização de CI com base numa revisão da literatura. Entre as diversas técnicas para caracterizar CI com CDs, nos estados líquido e sólido, tem-se a espectroscopia de absorção visível e ultravioleta, técnica de fluorescência, espectroscopia de Ressonância Magnética Nuclear, cromatografia líquida de alta eficiência, cristalográficas de Raio-X, estudos térmicos, espectroscopia de infravermelho com transformada de Fourier, microscopia eletrônica de varredura, espectroscopia de Raman, calorimetria de titulação isotérmica, ensaios de dissolução, dentre outros.

Cyclodextrins (CDs) are widely used in pharmaceutical product development, on account of their complexforming properties, mainly to increase the solubility of poorly soluble molecules. The lipophilic environment in the cavity of CDs provides favorable conditions for the formation of inclusion complexes (ICs) with hydrophobic compounds. Variations in the physicochemical properties of the guest molecules are identified by analytical methods that allow the formation of the complexes to be detected. This article is a discussion of the main methods used in the characterization of ICs, based on a review of the literature. There are many techniques available to characterize the CD-containing ICs, in the liquid and solid states, such as visible and ultraviolet absorption, fluorescence and nuclear magnetic resonance spectroscopy, high performance liquid chromatography, X-ray crystallography, thermal analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, isothermal titration calorimetry and dissolution tests.