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L Laforest

Publications and source records attributed to L Laforest.

26 records · Page 2Linked to original sources
PubMed1992

A unique secretory behavior for GP2 in the exocrine pancreas.

GP2 is the major glycoprotein component of the zymogen granule membrane of pancreas acinar cell. It was recently found that this protein is secreted and forms a network of fibrils in pancreatic juice. In the present work, with an ELISA, we have examined the fluctuations of GP2 levels in the juice collected in resting and stimulated conditions. In anaesthetized fasting rats, GP2 represented about 6-8% of total protein output. Stimulation by caerulein, carbachol, or their combination caused an immediate and significant burst in both protein and GP2 outputs. However, the GP2 increase did not parallel protein release. Its relative proportions decreased with the intensity of the stimulus. The secretory behavior of GP2 cannot be explained with the current concepts of constitutive and regulated pathways of secretion and suggests the existence of a yet undefined mode of secretion for this protein.

Animals↗
PubMed1989

Type of dietary lipids exerts a major influence on the secretory activity of the exocrine pancreas: medium-term studies.

A possible influence of the type of dietary lipids on the pancreas exocrine function was tested on rats. For this purpose, four groups of rats were fed on different diets comprising 5% of different types of lipids: fish oil, evening primose oil, hydrogenated beef tallow, and a mixture of fish oil and evening primose oil. After a 6 week feeding period, the secretory activity of the pancreas was measured. Under resting conditions, rats fed hydrogenated beef tallow release different proportions of amylase, lipase, and serine proteases as compared to rats fed unsaturated lipids. In stimulated conditions, there was no significant difference in the relative proportions of enzymes secreted by the pancreas among the different groups of rats but the secretory response to cerulein stimulation from rats fed saturated lipids was increased by more than 40%. These results demonstrate that the type of dietary lipids exerts a major influence on the secretory activity of the pancreas.

Animals↗
PubMedDate not supplied

[Is there an interaction between sleep-disordered breathing, depression and apolipoprotein E phenotype?].

Sleep-disordered breathing (SDB) is widely underdiagnosed among adults. However, SDB may be considered as a public health problem because of clinical consequences for the patient: impaired awake performance, increased risk factor for cardiovascular diseases and increased prevalence of depression. Apolipoprotein E (apoE), a protein involved in lipid metabolism, has 3 major alleles e2, e3 and e4. Recently, it has been shown that apoE e4 allele, a well-known risk factor for cardiovascular diseases, was also associated with SDB. In this study, we assessed a potential interaction between SDB, depression and apoE phenotype. 92 male patients (36-79 years old, mean age 58.0 11.2) consulting in hospital for SDB were enrolled in the study. Each patient had the following exams: 1) overnight polysomnography to determine apnea/hypopnea index (AHI=average number of respiratory events 10 seconds with no breathing per hour). A moderate-to-severe SDB was defined with AHI 15. 2) a psychiatric examination to look for previous or present symptoms of depressive illness. 3) blood sampling to determine apoE genotype (using PCR-RFLP method). In our study, allele frequencies for apoE e2, e3 and e4 were similar to those reported in general population. Among 92 patients, 68 (74%) presented moderate-to-severe SDB and 28 (30%) previous or present symptoms of depressive illness. Our results indicate that: 1) apoE e4 was significantly associated with moderate-to-severe SDB (n=92, p=0.03), 2) scores of apnea-hypopnea index were significantly higher in e4-positive versus e4-negative participants (n=57, p=0,05) and 3) ApoE and depression were not linked. This study confirms a potential interaction between SDB and apoE phenotype, as recently reported. This suggests that e4 allele might be a genetic risk factor for SDB (e4 allele frequency higher in patients with moderate-to-severe SDB versus general population) and/or consequently a deleterious factor for this pathology (increased AHI in e4-positive versus e4-negative patients). Depression might be only one of clinical consequences of SDB. Thus, SDB leads to repeated hypoxemia and numerous awakenings resulting in fatigue and decreased cognitive abilities suitable to the onset of depressive illness in vulnerable persons.

Adult↗