From Practice to Publication: The Promise of Writing Workshops

Practitioners in health departments, university extension programs, and nonprofit organizations working in public health face varied challenges to publishing in the peer-reviewed literature. These practitioners may lack time, support, skills, and efficacy needed for manuscript submission, which keeps them from sharing their wisdom and experience-based evidence. This exclusion can contribute to literature gaps, a failure of evidence-based practice to inform future research, reduced ability to educate partners, and delays in advancing public health practice. Our article describes the writing workshops offered to Division of Nutrition, Physical Activity, and Obesity (DNPAO), Centers for Disease Control and Prevention (CDC) funded programs in 2021. This project consisted of three 60-minute introductory writing webinars open to all recipients, followed by a Writing for Publications workshop, an 8- to 9-week virtual learning/writing intensive for selected writing team applicants. The Society for Public Health Education staff, consultants, and CDC/DNPAO staff developed, refined, and presented the curriculum. The workshop for public health practitioner writing teams was offered to two cohorts and included extensive coaching and focused on potential submission to a Health Promotion Practice supplement, “Reducing Chronic Disease through Physical Activity and Nutrition: Public Health Practice in the Field” (see Supplemental Material), which was supported by CDC/DNPAO. We describe the webinars, the workshop design, modifications, evaluation methods and results.

Differences in Resilience Mechanisms and Physical Activity among Women Experiencing Chronic Pain with Higher or Lower Resilience

BACKGROUND

Chronic pain is a public health issue, with women being disproportionately impacted. Progressing from light physical activity to the recommended moderate to vigorous intensities is effective for chronic pain self-management, yet participation is low among women experiencing chronic pain. Researchers studying resilience approaches to chronic pain contend that women with higher resilience, or functioning well despite adverse life stressors including chronic pain, should have better resilience mechanisms and more physical activity participation. The purpose of this work was to examine whether women experiencing chronic pain, reporting higher versus lower resilience, differed in resilience mechanisms (pain acceptance, self-regulatory efficacy to overcome pain and related barriers to activity, and self-regulatory efficacy to schedule and plan activity) and physical activity (light, moderate-vigorous).

METHODS

Adult women experiencing chronic pain (N = 269; M_age = 38.35, SD = 13.13 years) completed an online survey assessing study variables.

RESULTS

A multivariate analysis of covariance comparing participants with higher (n = 131) and lower (n = 138) resilience, controlling for age and pain intensity, was significant (p < .001; η²_partial = .17). Participants with higher resilience reported significantly higher pain acceptance, self-regulatory efficacy beliefs, and moderate-vigorous physical activity (p's < .01; η²_partial = .03 to .14, small to large effects). Light activity did not differ.

CONCLUSIONS

Novel findings illustrated that participants with higher resilience exhibited more favorable resilience mechanisms and participation in the recommended moderate-vigorous activity. If intervening among women with lower resilience to improve their resilience mechanisms and moderate-vigorous activity is effective, then intervention adoption and delivery across communities could promote improved pain self-management among women.

College Student Aerobic and Muscle-Strengthening Activity: The Intersection of Gender and Sexual Orientation Among United States Students

The purpose of the study was to examine differences in aerobic and muscle-strengthening activity participation based on the intersection of gender and sexual orientation among cisgender college students. Data from the American College Health Association National College Health Assessment collected between Fall 2015 and Fall 2018 were analyzed. Differences from the population average for meeting aerobic and muscle-strengthening activity (separately) recommendations were computed for each gender and sexual orientation intersection. The likelihood of meeting aerobic and muscle-strengthening activity (separately) recommendations were calculated using a series of logistic regression analyses to determine odds ratios controlling for age, year of enrollment, race/ethnicity, and health status. Overall, more men and those identifying as straight met activity (aerobic and muscle-strengthening) recommendations. Asexual and straight women were less likely to meet activity recommendations compared to men, and bisexual and questioning women were less likely to meet muscle-strengthening recommendations compared to men. Bisexual, pansexual, and questioning individuals were less likely to meet activity recommendations compared to straight individuals among both genders, as were queer and gay men and women who identified as pansexual or another identity. Men who identified as pansexual or another identity, as well as lesbian and queer women were less likely to meet muscle-strengthening recommendations compared to straight individuals. In summary, findings demonstrate that aerobic and muscle-strengthening activity participation disparities are evident based on the intersection of gender and sexual orientation. The intersection of socio-demographic characteristics should be considered by researchers and physical activity promoters in order to better understand and address disparities.

A proof-of-concept study on the impact of a chronic pain and physical activity training workshop for exercise professionals

OBJECTIVES

Physical activity is essential for long-term chronic pain management, yet individuals struggle to participate. Exercise professionals, including fitness instructors, and personal trainers, are preferred delivery agents for education and instruction on chronic pain, physical activity, and strategies to use adherence-promoting behavioral skills. However, exercise professionals receive no relevant training during certification or continuing education opportunities to effectively support their participants living with chronic pain. Based on the ORBIT model for early pre-efficacy phases of development and testing of new behavioral treatments, the present Phase IIa proof-of-concept study was conducted. The purpose was to examine the impacts of a newly developed chronic pain and physical activity training workshop on psychosocial outcomes among exercise professionals. Outcomes included knowledge and attitudes regarding chronic pain, attitudes and beliefs about the relationship between pain and impairment, and self-efficacy to educate and instruct participants with chronic pain.

METHODS

Forty-eight exercise professionals (M _age=44.4±11.0 years) participated in a three-hour, in-person workshop that was offered at one of four different locations. Participants completed pre- and post-workshop outcome assessment surveys.

RESULTS

Mixed MANOVA results comparing time (pre- versus post-workshop) by workshop location (sites 1 to 4) illustrated a significant within-subjects time effect (p<0.001). All outcomes significantly improved from pre- to post-workshop (p's<0.001), demonstrating large effect sizes (partial eta-squared values ranging from 0.45 to 0.59).

CONCLUSIONS

Findings offer early phase preliminary support for the effectiveness of the chronic pain and physical activity training workshop for exercise professionals. Based on ORBIT model recommendations, findings warrant future phased testing via a pilot randomized clinical trial as well as testing for impacts that trained professionals have on activity adherence among their clients living with chronic pain. Eventual workshop adoption by exercise professional certification organizations would ensure widespread and sustainable access to qualified exercise professionals to help individuals engage in physical activity. By increasing the capacity of available exercise professionals to deliver effective support, active individuals could better manage their chronic pain and live well.

Understanding Physiotherapists' Intention to Counsel Clients with Chronic Pain on Exercise: A Focus on Psychosocial Factors

Purpose: Twenty percent of Canadians experience chronic pain. Exercise is an effective management strategy, yet participation levels are low. Physiotherapists can be key to counselling clients to engage in long-term unsupervised exercise. Yet, investigations that identify psychosocial factors related to physiotherapists' intention to counsel are lacking. The purpose of this study was to examine whether physiotherapists' knowledge of chronic pain, beliefs about pain, and self-efficacy to counsel on exercise predicted their intention to counsel clients with chronic pain on exercise. Method: Practicing physiotherapists (N = 64) completed an online survey that assessed their knowledge of chronic pain, beliefs about pain, self-efficacy, and intention to counsel. A two-step hierarchical multiple regression predicted intention. Step 1 controlled for years of practice, and Step 2 included study variables significantly correlated with intention. Results: Beliefs about pain (r = -0.35, p < 0.01) and self-efficacy (r = 0.69, p < 0.01) were significantly correlated with intention. The overall regression model was significant, F _3,60 = 18.73; p < 0.001. Self-efficacy was the sole significant predictor, t ₆₀ = 5.71, p < 0.0001, sr ² = 28%. Conclusions: Self-efficacy may facilitate physiotherapists' intention to counsel on exercise for chronic pain. If shown to be a causal factor, interventions that target a change in physiotherapists' self-efficacy should be pursued.

Demographic Trends in Utah College Students' Vigorous Physical Activity, 2003-2007

OBJECTIVES

This analysis of a large-scale survey of college students from 2003 to 2007 explores relationships between meeting vigorous physical activity (VPA) recommendations and key demographic, lifestyle, and personal characteristics.

METHODS

Multivariate logistic regression modeling was used to analyze VPA data from the Utah Higher Education Health Behavior Survey, a descriptive cross-sectional survey conducted in 2003 (N = 4574), 2005 (N = 9673) and 2007 (N = 7938).

RESULTS

Factors consistently associated with meeting VPA recommendations included involvement in extracurricular sports, being single, and daily consumption of fruits or vegetables. In contrast, factors such as older age (> 23 years old), having a particularly low (<18.5 kg˙m2) or high BMI (> 34.9 kg˙m2), and being a current smoker were associated with not meeting the VPA recommendation. This corroborates paradoxical findings that binge alcohol consumption correlates with meeting VPA.

CONCLUSIONS

Findings support the need for targeted interventions among college students to support the establishment of long-term protective behavioral patterns against chronic disease risk throughout the life course.

Differences in psychosocial responses to pain between sufficiently and insufficiently active adults with arthritis

OBJECTIVE

Adults with arthritis struggle to meet the physical activity recommendation for disease self-management. Identifying psychosocial factors that differentiate adults who meet (sufficiently active) or do not meet (insufficiently active) the recommendation is needed. This study sought to examine differences in psychosocial responses to arthritis pain among adults who were sufficiently or insufficiently active.

DESIGN

This prospective study included adults with medically diagnosed arthritis (N = 136, M_age = 49.75 ± 13.88 years) who completed two online surveys: (1) baseline: pain and psychosocial responses to pain and (2) two weeks later: physical activity.

MAIN OUTCOME MEASURES

Psychosocial responses examined in this study were psychological flexibility in response to pain, pain anxiety and maladaptive responses to pain anxiety.

RESULTS

A between-groups MANCOVA comparing sufficiently active (n = 87) to insufficiently active (n = 49) participants on psychosocial responses, after controlling for pain intensity, was significant (p = .005). Follow-up ANOVA's revealed that sufficiently active participants reported significantly higher psychological flexibility and used maladaptive responses less often compared to insufficiently active participants (p's < .05).

CONCLUSIONS

These findings provide preliminary insight into the psychosocial profile of adults at risk for nonadherence due to their responses to arthritis pain.

Barriers to Physical Activity Among Gay Men

Gay men may not be physically active at recommended levels to achieve health benefits. Thus, a need exists to identify general (i.e., common across populations) and population-specific barriers that hinder or stop gay men from participating in physical activity (PA). Salient barriers may be identified through the extent each barrier limits PA (i.e., barrier limitation) and the level of one’s confidence to overcome barriers and engage in PA (i.e., self-regulatory efficacy). The purposes of this study were to (1) provide a description of general and population-specific barriers to PA among sufficiently and insufficiently active gay men, (2) identify barrier limitation and self-regulatory efficacy for the reported barriers, and (3) examine the associations between meeting the current PA recommendation, barrier limitation, and self-regulatory efficacy. Participants were 108 self-identified gay males aged 21 to 64 years who completed a web-based survey. A total of 35 general barriers and no population-specific barriers were identified by the sufficiently and insufficiently active groups. The sufficiently active group reported higher self-regulatory efficacy and lower barrier limitation for nearly all reported barriers. A binary logistic regression used to examine the associations between PA, barrier limitation, and self-regulatory efficacy was statistically significant, χ2(2, N = 108) = 19.26, p < .0001, R2 = .16. Only barrier limitation significantly contributed to the model. Future research should continue to examine barriers to PA among gay men to determine whether an intervention needs to be designed specifically for gay men or whether a one-size-fits-all intervention would be effective in helping all men overcome common barriers to engaging in PA.

An Examination of Health Inequities among College Students by Sexual Orientation Identity and Sex

Background

Lesbian, gay, and bisexual (LGB) college students may have an increased number of health inequities compared to their heterosexual counterparts. However, to date, no research has provided a comprehensive examination of health-related factors by sexual orientation identity and sex among a national sample of college students. Thus, the purpose of this study was to examine physical, sexual, interpersonal relations/safety, and mental health inequities by sexual orientation identity and sex among a national sample of college students.

Design and methods

Participants (n=39,767) completed the National College Health Assessment II during the fall 2008/spring 2009 academic year. Hierarchical binary logistic regression analyses were used to examine health inequities by sexual orientation identity and sex.

Results

LGB students compared to heterosexual students, experienced multiple health inequities including higher rates of being verbally threatened and lower rates of physical activity and condom use.

Conclusions

An understanding of health inequities experienced by LGB college students is critical as during these years of transition, students engage in protective (e.g., physical activity) and risky (e.g., lack of condom use) health behaviours, establishing habits that could last a lifetime. Future research should be used to design and implement targeted public health strategies and policies to reduce health inequities and improve health-related quality of life among LGB college students.

The Effect of an 8-Week Tai Chi Exercise Program on Physical Functional Performance in Middle-Aged Women

The purpose of this study was to determine the effectiveness of an 8-week Tai Chi Chih exercise program on physical functional performance (PFP) among women aged 45 to 65 years. A quasi-experimental design with a nonequivalent comparison group was used. Forty-one healthy inactive women were assigned to either an intervention group (n = 19) or a comparison group (n = 19). A 60-min Tai Chi Chih exercise class was conducted twice a week for 8 weeks. PFP was measured at baseline and postintervention using the Continuous Scale Physical Functional Performance-10 (CS-PFP 10). Between-group differences were analyzed using one-way analysis of covariance (ANCOVA). After participating in the 8-week program, intervention group participants showed greater improvement in the CS-PFP measures (p < .05, η(2) > .06). However, the comparison group had little changes. The findings from this study suggest that participation in an 8-week Tai Chi Chih exercise program can improve PFP in healthy, community-dwelling middle-aged women.

Associations between physical activity and health-related factors in a national sample of college students

OBJECTIVE

To examine associations between meeting the current moderate to vigorous physical activity (MVPA) recommendation and health-related factors in a national sample of college students.

PARTICIPANTS

Participants (N = 67,861) completed the National College Health Assessment II during the Fall 2008/Spring 2009 academic year.

METHODS

Hierarchical binary logistic regression was used to examine the contribution of 19 variables in explaining whether or not participants met the MVPA recommendation.

RESULTS

Meeting the MVPA recommendation was associated with several protective factors among college students, including adequate daily fruit and vegetable consumption, positive perception of general health, healthy body mass index, consistent seatbelt use, not smoking cigarettes, less perceived depression, and adequate sleep. In addition, meeting the MVPA recommendation was also significantly associated with a few risky behaviors including binge drinking, physical fighting, and multiple sexual partners.

CONCLUSIONS

College student PA interventions should consider also addressing fruit/vegetable consumption and binge drinking.

Sociodemographic and lesbian-specific factors associated with physical activity among adult lesbians

BACKGROUND

Although participation in moderate and vigorous physical activity (MVPA) results in health benefits, the majority of adult lesbians are not sufficiently active. The purpose of this study was to examine the relationships between sociodemographic factors (age, education level, body mass index [BMI], race, partner status, employment status, annual household income, general health status, diagnosis of chronic conditions, children under 18 years living at home) and lesbian-specific factors (connection with the lesbian community, public identification as a lesbian) to participation in MVPA.

METHODS

Participants included 847 self-identified lesbians 18 to 74 years old (M(age) = 40.5; SD = 11.6) who completed a 20-minute, web-based survey.

FINDINGS

The binary logistic regression model that included the 10 demographic factors was significantly associated with MVPA, χ(2) (15, N = 847) = 105.62, p < .001. However, when the two lesbian-specific factors were added, the model did not improve significantly, χ(2) (2, N = 847) = 5.20, p = .07. BMI and general health status were significantly associated with MVPA (Wald χ(2) (2) = 19.5, p < .001) and (Wald χ(2) (4) = 41.2, p < .001). Obese participants had 54.5% lower odds than healthy weight participants to engage in sufficient amounts of MVPA. Participants who reported general health status as excellent compared with those who reported poor had 12.7 times greater odds of engaging in sufficient amounts of MVPA.

CONCLUSIONS

Future research should extend on this study by utilizing sampling methods that target the recruitment of lesbian women not actively involved in lesbian-related activities.

Perceptions of Trained Leaders on Improving the Public Health Impact of Three Arthritis Foundation Programs

The Arthritis Foundation (AF) offers effective community-based programs to help manage arthritis, including aquatic, exercise, and self-help programs. Trained leaders can facilitate the adoption, maintenance, and reach of these programs and thus the impact on public health. This study identifies reasons for becoming AF aquatic, exercise, and/or self-help program leaders, AF program reach, and adoption and maintenance challenges encountered by individuals after being trained. Researchers interviewed by telephone 72 participants who attended an AF leader training workshop. Participants reported various reasons for becoming program leaders (e.g., a wish to help others). AF programs were mainly adopted and maintained in urban communities and in fitness/ health clubs, medical centers, or senior centers. Aquatics programs were the most frequently offered, and all programs had low reach (with a mean number of participants of 14.41, 12.50, and 11.00 for aquatic programs, exercise programs, and self-help programs, respectively. Challenges to adopting and maintaining programs include the time of year (e.g., winter, holidays) and lack of a facility to offer the program.

Partial Examination of the Public Health Impact of the People with Arthritis Can Exercise (PACE�) Program: Reach, Adoption, and Maintenance

OBJECTIVE

To partially evaluate the public health impact (i.e., reach, adoption, maintenance) of People with Arthritis Can Exercise (PACE) programs, which were initiated as a result of two PACE instructor-training workshops.

DESIGN

The study design involved a one-time only, cross-sectional assessment of reach, adoption, and maintenance, conducted 6 months after the workshops.

SAMPLE

Participants were 11 adults (n(females)=10) trained to be PACE instructors at one of the workshops.

MEASUREMENTS

One-on-one phone interviews, developed using the RE-AIM framework, assessed reach, adoption, and maintenance.

RESULTS

Eight of the 11 individuals trained as instructors subsequently began PACE in one of 10 organizations across various communities, indicating high program adoption. However, on average, only 7 individuals with arthritis participated in each PACE program, indicating a low program reach. Within 6 months of beginning PACE, only 3 organizations continued to offer PACE, indicating low program maintenance. Two primary challenges to initiating PACE included recruiting a sufficient number of people to participate in the program and in finding a convenient time to offer it so more individuals could join.

CONCLUSION

The public health impact, as assessed by reach, adoption, and maintenance, of PACE programs initiated as a result of 2 instructor-training workshops was low.

Barriers to Moderate Physical Activity in Adult Lesbians

Adult lesbians are not sufficiently physically active to achieve physical and psychological health benefits. Lesbians are one of the least understood minority groups. Therefore, the purpose of this study was to use an ecological framework to identify factors internal to individuals and present in their social environments that may impede participation in regular physical activity. Twenty-one self-identified lesbians aged 22 to 61 years participated in one of four focus groups. The lesbian participants reported many general barriers (i.e., obstacles to participation regardless of sexual orientation) similar to previous research with other populations of women, not stratified by sexual orientation, such as being too tired and the lack of a physical activity partner. A number of lesbian-specific barriers (i.e., obstacles unique to being a lesbian) were also identified, such as the lack of lesbian-focused physical activity groups and the lack of same-sex family memberships to fitness facilities. In conclusion, for many of the general barriers, some of the proven and effective traditional intervention strategies are likely to be effective in increasing physical activity participation rates in the lesbian population. However, barriers related to sexual orientation are likely deeply entrenched in the socio-cultural system of American society and require a societal rethinking of attitudes towards lesbians, a cultural change that is not as easily amenable to traditional health promotion interventions.

Coping with barriers to vigorous physical activity during transition to university

This study examined barriers to vigorous physical activity (VPA) among 132 students transitioning from high school to the first year of a university. An ecological framework was used to classify barriers, and coping self-efficacy (CSE) and task self-efficacy (TSE) were investigated as predictors of VPA. Consistent with population data, 47% of the sample failed to meet national recommendations for VPA. Participants most often cited institutional, intrapersonal, and interpersonal barriers. CSE predicted TSE, which predicted VPA. A greater understanding of ecologically categorized barriers and the relationship of self-efficacy to VPA may aid health care practitioners in the design of targeted interventions to facilitate VPA and health among freshmen students.

Kinetic characteristics of ZENECA ZD5522, a potent inhibitor of human and bovine lens aldose reductase

Aldose reductase (aldehyde reductase 2) catalyses the conversion of glucose to sorbitol, and methylglyoxal to acetol. Treatment with aldose reductase inhibitors (ARIs) is a potential approach to decrease the development of diabetic complications. The sulphonylnitromethanes are a recently discovered class of aldose reductase inhibitors, first exemplified by ICI215918. We now describe enzyme kinetic characterization of a second sulphonylnitromethane, 3',5'-dimethyl-4'-nitromethylsulphonyl-2-(2-tolyl)acetanilide (ZD5522), which is at least 10-fold more potent against bovine lens aldose reductase in vitro and which also has a greater efficacy for reduction of rat nerve sorbitol levels in vivo (ED95 = 2.8 mg kg-1 for ZD5522 and 20 mg kg-1 for ICI 215918). ZD5522 follows pure noncompetitive kinetics against bovine lens aldose reductase when either glucose or methylglyoxal is varied (K(is) = K(ii) = 7.2 and 4.3 nM, respectively). This contrasts with ICI 215918 which is an uncompetitive inhibitor (K(ii) = 100 nM) of bovine lens aldose reductase when glucose is varied. Against human recombinant aldose reductase, ZD5522 displays mixed noncompetitive kinetics with respect to both substrates (K(is) = 41 nM, K(ii) = 8 nM with glucose and K(is) = 52 nM, K(ii) = 3.8 nM with methylglyoxal). This is the first report of the effects of a sulphonylnitromethane on either human aldose reductase or utilization of methylglyoxal. These results are discussed with reference to a Di Iso Ordered Bi Bi mechanism for aldose reductase, where the inhibitors compete with binding of both the aldehyde substrate and alcohol product. This model may explain why aldose reductase inhibitors follow noncompetitive or uncompetitive kinetics with respect to aldehyde substrates, and X-ray crystallography paradoxically locates an ARI within the substrate binding site. Aldehyde reductase (aldehyde reductase 1) is closely related to aldose reductase. Inhibition of bovine kidney aldehyde reductase by ZD5522 follows uncompetitive kinetics with respect to glucuronate (K(ii) = 39 nM), indicating a selectivity greater than 5-fold for bovine aldose reductase relative to aldehyde reductase.

Inhibition of aldose reductase by (2,6-dimethylphenylsulphonyl)nitromethane: possible implications for the nature of an inhibitor binding site and a cause of biphasic kinetics

Aldose reductase (aldehyde reductase 2, ALR2) is often isolated as a mixture of two forms which are sensitive (ALR2S), or insensitive (ALR2I), to inhibitors. We show that ICI 215918 ((2-6-dimethylphenylsulphonyl)-nitromethane) follows either noncompetitive, or uncompetitive kinetics with respect to aldehyde for ALR2S, or the closely related enzyme, aldehyde reductase (aldehyde reductase 1, ALR1). Similar behaviour is exhibited by two other structural types of aldose reductase inhibitor (ARI), spirohydantoins and acetic acids, when either aldehyde, or NADPH is varied. For ALR2S, we have demonstrated kinetic competition between a sulphonylnitromethane, an acetic acid and a spirohydantoin. Thus, different ARIs probably have overlapping binding sites. Published studies imply that ALR2 follows an ordered mechanism where coenzyme binds first and induces a reversible conformation change (E.NADPH-->E*.NADPH). Reduction of aldehyde appears rate-limited by the step E*.NADP+-->E.NADP+. Spontaneous activation converts ALR2S into ALR2I and increases kcat. This must be associated with acceleration of the rate-determining step. We now propose the following hypothesis to explain characteristics of ARIs. (1) Inhibitors preferentially bind to the E* conformation. (2) The ARI binding site contains residues in common with that for aldehyde substrates. When aldehyde is varied, uncompetitive inhibition arises from association at the site for alcohol product in the E*.NADP+ complex which has little affinity for the substrate. Any competitive inhibition arises from use of the aldehyde site in the E*.NADPH complex. (3) Acceleration of the E*.NADP+-->E.NADP+ step upon activation of ALR2 reduces steady state levels of E* and so decreases sensitivity to ARIs.

(2,6-Dimethylphenylsulphonyl)nitromethane: a new structural type of aldose reductase inhibitor which follows biphasic kinetics and uses an allosteric binding site

Many of the complications of diabetes seem to be due to aldose reductase (aldehyde reductase 2, ALR2) catalysing the increased conversion of glucose to sorbitol. Therapy with aldose reductase inhibitors (ARIs) could, therefore, decrease the development of diabetic complications. (2,6-Dimethylphenylsulphonyl)nitromethane (ICI 215918) is an example from a newly discovered class of ARIs, and we here describe its kinetic properties. Preparations of bovine lens ALR2 exhibit biphasic kinetics with respect to glucose and various inhibitors including ICI 215918. The inhibitor sensitive form (ALR2S) has a higher affinity for glucose than does the inhibitor insensitive form (ALR2I). Only ALR2S was characterized in detail because ALR2I activity is very low at physiological levels of glucose and is difficult to measure with accuracy. Aldehyde reductase (ALR1) is the most closely related enzyme to ALR2. Inhibition of ALR1 was, therefore, investigated in order to assess the specificity of ICI 215918. The values of Ki and Kies (dissociation constants for inhibitor from enzyme-inhibitor and enzyme-inhibitor-substrate complexes, respectively) for ICI 215918 with bovine kidney ALR1 and bovine lens ALR2S have been determined. When glucose is varied, the compound is an uncompetitive inhibitor of ALR2S (Kies = 0.10 microM and Ki is much greater than Kies), indicating that ICI 215918 associates with an allosteric site on the enzyme. These kinetic characteristics would cause a decrease in the concentration required to give 50% inhibition when glucose levels rise during hyperglycaemia. ICI 215918 is a mixed noncompetitive inhibitor of ALR1 (Ki = 10 microM and Kies = 1.8 microM) when glucuronate is varied. Thus, the compound has up to 100-fold specificity in favour of ALR2S relative to ALR1. Therapeutic interest has now centred upon at least three distinct structural types of ARIs: spirohydantoins, acetic acids and sulphonylnitromethanes. Using one representative of each type, we have demonstrated kinetic competition for inhibition of ALR2S. This observation strongly suggests that the different inhibitors use overlapping binding sites.

Purified rat lens aldose reductase. Polyol production in vitro and its inhibition by aldose reductase inhibitors

The production of polyols in vitro by highly purified aldose reductase (EC 1.1.1.21) was monitored by g.l.c. In the presence of NADPH aldose reductase reduced glucose, galactose and xylose to the respective polyols sorbitol, galactitol and xylitol. The rates of formation of these polyols closely mirrored the Km values for the substrates obtained from kinetic measurements that monitored the rate of disappearance of NADPH. No polyol production occurred in the absence of purified aldose of purified aldose reductase, and analysis by g.l.c. revealed only the presence of unchanged monosaccharides. Addition of the aldose reductase inhibitor sorbinil to purified rat lens aldose reductase incubated with xylose in the presence of NADPH resulted in decreased xylitol production. However, aldose reductase inhibitors produced no effect in altering the rate of Nitro Blue Tetrazolium formation from either glucose or xylose, indicating that the observed inhibition in vitro does not result from a free-radical-scavenger effect.